What change would increase the amount of solid solute able to be dissolved in liquid water?
Decreasing rate of stirring
Decreasing surface area
Increasing pressure
Increasing temperature

Answers

Answer 1

Answer:

D: Increasing temperature

Explanation:

From collision theory, we know that the more the increase in collisions, the faster the rate of the chemical reaction.

Now, the amount of solid solute in a solvent will change with a corresponding change in temperature. What we mean is that, the higher the temperature increases, the higher the number of collisions between the solvent molecules as well as leading to an increase in the solute particles which will mean an increase in the amount of the solid solute dissolved. The correct answer is option D.

Answer 2

Answer:

Increasing temperature.

Explanation:


Related Questions

What intermolecular force or bond is primarily responsible for the solubility of chlorine (Cl2) in water

Answers

The question is incomplete, the common question is;

What intermolecular attractive force is primarily responsible for the solubility of chlorine, Cl2, in water?

a. dipole - dipole

b. hydrogen bonding

c. dipole-induced dipole

d. ion-dipole

e. ion-induced dipole

Answer:

dipole-induced dipole

Explanation:

We have to remember that water is a polar molecule hence it possesses a dipole moment. Its dipole moment is responsible for the ability of water to dissolve many substances.

On the other hand, Cl2 is a nonpolar molecule bound together by only weak dispersion forces.

Recall that dispersion forces involve transient appearance of a dipole in a molecule.

Water molecules can induce a dipole in Cl2 thereby causing the both molecules to interact and Cl2 dissolves in water.

What is the empirical formula for a compound if 300.00 g of it is known to contain 82.46224 g of molybdenum, 45.741 g of chlorine and the rest is bromine

Answers

Answer:

MoClBr₂

Explanation:

First we calculate the mass of bromine in the compound:

300.00 g - (82.46224 g + 45.741 g) = 171.79676 g

Then we calculate the number of moles of each element, using their respective molar masses:

82.46224 g Mo ÷ 95.95 g/mol = 0.9594 mol Mo45.741 g Cl ÷ 35.45 g/mol = 1.290 mol Cl171.79676 g Br ÷79.9 g/mol = 2.150 mol Br

Now we divide those numbers of moles by the lowest number among them:

0.9594 mol Mo / 0.9594 = 11.290 mol Cl / 0.9594 = 1.34 ≅ 12.150 mol Br / 0.9594 = 2.24 ≅ 2

Meaning the empirical formula is MoClBr₂.

Suppose an electron is transferred from a potassium atom to an unknown halogen atom. For which of the following halogen atoms would this process require the least amount of energy?
A. Cl
B. Br
C. I

Answers

Answer:

Cl

Explanation:

Electronegativity is the ability of an electron to attract electrons.

Now, due to the fact that halogens need just one more electron to become stable in their outermost shell, it means all halogens are electronegative.

However, the smaller the atomic number, the bigger the charge density and thus the more electronegative.

Thus, it is the halogen element with the highest atomic number further down the periodic table that will have the least electro negativity and thus require highest amount of energy to attract other electrons.

Thus, since chlorine (Cl) has the least atomic number of 17, then it means that it will be the one that will easily accept the electrons the most from other elements. Therefore the process of transferring electrons from potassium to chlorine will take the least amount of energy.

Which is the primary type of radiation from the sun that is absorbed by the ozone layer?
A. infrared radiatin
B. UV-B
C. X-rays
D. UV-C
E. UV-A

Answers

the answer to the question is B.UV-B

5. The Rf of ibuprofen was found to be 0.32 when t-butyl methyl ether was used as the development solvent. What effect would there be on the Rf of ibuprofen if acetone had been used to develop the TLC plate?

Answers

Answer:

The Rf value of ibuprofen increases

Explanation:

TLC involves the elution of a solute using a mobile phase(solvent). The stationary phase is made of an adsorbent such as silica.

The extent of interaction between the solute and the mobile phase affects the Rf value. The greater the interaction between the solute and the solvent, the greater the Rf value.

On the other hand, the polarity of the solvent and the solute also affects the Rf value. If the solvent is changed from t-butyl methyl ether to acetone, the Rf value for ibuprofen increases because ibuprofen is polar and acetone is also polar hence there is greater interaction between the solvent and solute.

Calculate the osmotic pressure of 5.0g of sucrose ssolution in 1L. Answer should be in Torr

Answers

Answer: The osmotic pressure of 5.0g of sucrose solution in 1 L is 271.32 torr.

Explanation:

Given: Mass = 5.0 g

Volume = 1 L

Molar mass of sucrose = 342.3 g/mol

Moles are the mass of a substance divided by its molar mass. So, moles of sucrose are calculated as follows.

[tex]Moles = \frac{mass}{molarmass}\\= \frac{5.0 g}{342.3 g/mol}\\= 0.0146 mol[/tex]

Hence, concentration of sucrose is calculated as follows.

[tex]Concentration = \frac{moles}{Volume (in L)}\\= \frac{0.0146 mol}{1 L}\\= 0.0146 M[/tex]

Formula used to calculate osmotic pressure is as follows.

[tex]\pi = CRT[/tex]

where,

[tex]\pi[/tex] = osmotic pressure

C = concentration

R = gas constant = 0.0821 L atm/mol K

T = temperature

Substitute the values into above formula as follows.

[tex]\pi = CRT\\= 0.0146 \times 0.0821 L atm/mol K \times 298 K\\= 0.357 atm (1 atm = 760 torr)\\= 271.32 torr[/tex]

Thus, we can conclude that the osmotic pressure of 5.0g of sucrose solution in 1 L is 271.32 torr.

Choose the correct statement. A) The cathode is the electrode where the oxidation takes place. B) The cathode is the electrode where the reduction takes place. C) Both oxidation and reduction may take place at the cathode, depending on the cell. D) The cathode is always positive

Answers

B. The cathode is the electrode where the reduction takes place took test


Organic foods do not contain chemicals.

True
False

Answers

True because they are organically made without any things that include chemicals

The blank is the accepted form of gathering and reporting information within the science community.

Answers

Answer:

Scientific method.

Explanation:

Scientific method is the way taken to acquire scientific knowledge. It includes experiments, statistical analysis of existing data, and all kinds of observations of the world around us, while theoretical research is based on deriving certain theories about the world from basic principles, in a mathematical or logical way. The scientific method applies to both types of research, and emphasizes that scientific research is objective, that it can be verified by other scientists, and that knowledge is not acquired without context, but in a way that leads to a greater understanding of previous research and the world. we live in. To contribute to this, researchers are expected to clearly record both their findings and the methods they use to arrive at the results.

You are asked to prepare a buffer solution with a pH of 3.50. The following solutions, all 0.100 M, are available to you: HCOOH, CH3COOH, H3PO4 , NaCHOO, NaCH3COO, and NaH2PO4.  What would be the best combination to make the required buffer solution? Select one:
a. NaH2PO4 and NaCHOO  
b. H3PO4 and NaH2PO4
c. NaH2PO4 and HCOOH
d. CH3COOH and NaCH3COO e. HCOOH and NaCHOO
can someone helo me with this​

Answers

Answer:

e. HCOOH and NaCHOO

Explanation:

For a buffer solution, both an acid and its conjugate base are required.

With the information above in mind, we can discard options a) and c), as those combinations are not of an acid and its conjugate base.

Now it is a matter of comparing the pKa (found in literature tables) of the acids of the remaining three acids:

H₃PO₄ pKa = 2.12CH₃COOH pKa = 2.8HCOOH pKa = 3.74

The acid with the pKa closest to the desired pH is HCOOH, so the correct answer is e. HCOOH and NaCHOO

g You observed the formation of several precipitates in the Reactions in Solution lab exercise. Identify the precipitate in each of the following reactions: a. The yellow precipitate formed in the reaction between KI and Pb(NO3)2 is . b. The white precipitate formed in the reaction between BaCl2 and H2SO4 is . c. The brown precipitate formed in the reaction between NaOH and FeCl3 is . d. The blue precipitate formed in the reaction between CuSO4 and NaOH is .

Answers

Answer:

For a: Lead iodide is a yellow precipitate.

For b: Barium sulfate is a white precipitate.

For c: Ferric hydroxide is a brown precipitate.

For d: Copper (II) hydroxide is a blue precipitate.

Explanation:

Precipitation reaction is defined as the reaction where a solid precipitate (solid substance) is formed at the end of the reaction. It is insoluble in water.

For the given options:

For (a):

The chemical reaction between KI and lead (II) nitrate follows:

[tex]2KI(aq)+Pb(NO_3)_2(aq)\rightarrow PbI_2(s)+2KNO_3(aq)[/tex]

The iodide of lead is generally insoluble in water. Thus, lead iodide is a yellow precipitate.

For b:

The chemical reaction between barium chloride and sulfuric acid follows:

[tex]BaCl_2(aq)+H_2SO_4(aq)\rightarrow BaSO_4(s)+2HCl(aq)[/tex]

The sulfate of barium is insoluble in water. Thus, barium sulfate is a white precipitate.

For c:

The chemical reaction between NaOH and ferric chloride follows:

[tex]3NaOH(aq)+FeCl_3(aq)\rightarrow Fe(OH)_3(s)+3NaCl(aq)[/tex]

The hydroxide of iron is insoluble in water. Thus, ferric hydroxide is a brown precipitate.

For d:

The chemical reaction between NaOH and copper sulfate follows:

[tex]CuSO_4+2NaOH\rightarrow Cu(OH)_2+Na_2SO_4[/tex]

The hydroxide of copper is insoluble in water. Thus, copper (II) hydroxide is a blue precipitate.

(a) The yellow precipitate formed in the reaction between KI and Pb(NO3)2 would be PbI2 according to the equation:

[tex]Pb(NO_3)_2(aq) + 2KI(aq) ---> PbI2(s) + 2KNO_3(aq)[/tex]

(b) The white precipitate formed in the reaction between BaCl2 and H2SO4 would be  BaSO4 according to the equation:

   [tex]BaCl_2 (aq) + H_2SO_4 (aq) ---> BaSO_4 (s) + 2 HCl (aq)[/tex]

(c) The brown precipitate formed in the reaction between NaOH and FeCl3 would be Fe(OH)3 according to the equation:

[tex]FeCl_3 (aq) + NaOH (aq) ---> Fe(OH)_3 (s) + NaCl (aq)[/tex]

(d) The blue precipitate formed in the reaction between CuSO4 and NaOH would be Cu(OH)2 according to the equation:

[tex]CuSO_4(aq) + 2 NaOH (aq) ---> Cu(OH)_2 (s) + Na_2SO_4 (aq)[/tex]

More on precipitation reaction can be found here: https://brainly.com/question/24846690

Give the symbol for an element that is:__________

a. a halogen: _______________
b. an alkali metal: _______________
c. a noble gas: _______________
d. an alkaline earth metal : ____________

Answers

a. Br, Cl, F

b. Na, K, Ba

c. He, Ar, Ne

d. Ca, Ba, Mg

Answer:

a. halogen : F ,Cl ,Br l ,At

b an alkali metal: Na,Li, Rb, Cs

c. a noble gas: He, Ne, Kr, Ar

d. an alkaline earth metal: Be,Mg,Ca, Sr

hope it helps

stay safe healthy and happy...

15. You are interested in separating 4-methylbenzoic acid from 1,4-dimethoxybenzene using a procedure similar to the extraction procedure we used in lab. You plan to use sodium bicarbonate instead of sodium hydroxide. a) Show the reaction between salicylic acid and sodium bicarbonate. Label the acid, base, conjugate acid, conjugate base. b) Give the pKa values of the acid and conjugate acid. c) Which base will work better, sodium hydroxide or sodium bicarbonate

Answers

Solution :

a). The separation of 4-methylbenzoic acid from 1,4-dimethoxybenzene will work but it will result in lower recovery.

In the reaction of acid-base to form a sodium 4 - methoxy benzoate, that is soluble in the water, 4-methoxy benzoic acid reacts with the sodium bicarbonate to give sodium 4-methoxybenzoate as well as carbonic acid.

b). The pKa for the 4-methoxybenzoic acid is [tex]4.46[/tex], and that of carbonic acid is [tex]6.37[/tex]

c). The Keq for the reaction is [tex]10(6.37 - 4.46) = 101.91[/tex]

Therefore, the equilibrium lies to the right  and also the reaction favors the products and the separation works.

But the recovery will be low when compared to the extraction with Sodium hydroxide as the strong base will drive the equilibrium further to the right position, thus neutralizing all the acids virtually. And the weak base will partially neutralize the acid.

Based on the equations below, which metal is the least active? Pb(NO3)2(aq) + Ni (s) --> Ni(NO3)2 (aq)+ Pb(s) Pb(NO3)2(aq) + Ag(s) --> No reaction Cu(

Answers

Answer:

Ni

Explanation:

An active metal is a highly reactive metal. Active metals are found high up in the activity series.

Active metals react with other metals that are lower than them in the activity thereby displacing the lower metals from a solution of their salts. This is what may have happened in the other two reactions.

Ni is the most active metal listed in the question since it can react a compounds with Pb(NO3)2(aq) to liberate Pb metal.

Indicate if the following are the correct ground state electron configurations
for the atom listed by choosing correct or incorrect from the drop down menu.
1. Cr: [Ar]4s03d6
2. Zr: [Kr]5s23f144d2
3. Fe: [Ar]4s23d6
4. Co3+: [Ar]4s03d6
5. Ti2+: [Ar]4s03d2
6. Cu+: [Ar]4s23d8

Answers

Answer:

1) incorrect

2) incorrect

3) correct

4) correct

5) correct

6) incorrect

Explanation:

The correct electronic configuration of chromium is; [Ar] 3d⁵ 4s¹

The correct electronic configuration for Zr is; [Kr] 4d² 5s²

The correct electronic configuration of Cu^+ is; [Ar] 3d¹⁰

The electronic configuration of an atom refers to the arrangement of electrons in the atoms of such element.

The appropriate number of electrons and its properly written electronic configuration is clearly shown in this answer.

What does the term spontaneous mean in chemical reactions?
A. Producing heat as a product
B. Occurring without added energy
C. Occurring only at high temperatures
D. Occurring in an aqueous solution

Answers

Answer:

B

Explanation:

Spontaneous in chemical reactions means without any external input.

Occurring without added energy. Hence, option B is correct.

What is a spontaneous reaction?

A spontaneous reaction is a reaction that supports the formation of products under the conditions under which the reaction is happening.

Spontaneous Reaction- a reaction that favours the formation of products at the conditions under which the reaction is occurring.

A non-spontaneous reaction can be made spontaneous if it is inside a controlled environment, this is what happens in nuclear power plants that create atomic fusion and fission in chambers that are controlled to control different particles to create nuclear active rays.

Hence, option B is correct.

Learn more about the spontaneous reaction here:

brainly.com/question/23142328

#SPJ5

Which statement is about population density

Answers

Explanation:

Population density is defined as the number of people present per square kilometre. Population density of India according to 2011 census is 382 persons per square kilometres.

Consider the titration of 30 mL of 0.030 M NH3 with 0.025 M HCl. Calculate the pH after the following volumes of titrant have been added: a) 0 mL; b) 10 mL; c) 20 mL; d)35 mL; e) 36 mL; f) 37 mL.

Answers

Answer:

a)10.87

b)9.66

c)9.15

d)7.71

e) 5.56

f) 3.43

Explanation:

tep 1: Data given

Volume of 0.030 M NH3 solution = 30 mL = 0.030 L

Molarity of the HCl solution = 0.025 M

Step 2: Adding 0 mL of HCl

The reaction:    NH3 + H2O ⇔ NH4+ + OH-

The initial concentration:  

[NH3] = 0.030M    [NH4+] = 0M    [OH-] = OM

The concentration at the equilibrium:

[NH3] = 0.030 - XM

[NH4+] = [OH-] = XM

Kb = ([NH4+][OH-])/[NH3]

1.8*10^-5 = x² / 0.030-x

1.8*10^-5 = x² / 0.030

x = 7.35 * 10^-4 = [OH-]

pOH = -log [7.35 * 10^-4]

pOH = 3.13

pH = 14-3.13 = 10.87

Step 3: After adding 10 mL of HCl

The reaction:

NH3 + HCl ⇔ NH4+ + Cl-

NH3 + H3O+ ⇔ NH4+ + H2O

Calculate numbers of moles:

Moles of NH3 = 0.030 M * 0.030 L = 0.0009 moles

Moles HCl = 0.025 M * 0.010 L = 0.00025 moles

Moles NH4+ = 0 moles

Number of moles at the equilibrium:

Moles NH3 = 0.0009 -0.00025 =0.00065 moles

Moles HCl = 0

Moles NH4+ = 0.00025 moles

Concentration at the equilibrium:

[NH3]= 0.00065 moles / 0.040 L = 0.01625M

[NH4+] = 0.00625 M

pOH = pKb + log [NH4+]/[NH3]

pOH =  4.75 + log (0.00625/0.01625)

pOH = 4.34

pH = 9.66

Step 3: Adding 20 mL of HCl

Calculate numbers of moles:

Moles of NH3 = 0.030 M * 0.030 L = 0.0009 moles

Moles HCl = 0.025 M * 0.020 L = 0.00050 moles

Moles NH4+ = 0 moles

Number of moles at the equilibrium:

Moles NH3 = 0.0009 -0.00050 =0.00040 moles

Moles HCl = 0

Moles NH4+ = 0.00050 moles

Concentration at the equilibrium:

[NH3]= 0.00040 moles / 0.050 L = 0.008M

[NH4+] = 0.01 M

pOH = pKb + log [NH4+]/[NH3]

pOH =  4.75 + log (0.01/0.008)

pOH = 4.85

pH = 14 - 4.85 = 9.15

Step 4: Adding 35 mL of HCl

Calculate numbers of moles:

Moles of NH3 = 0.030 M * 0.030 L = 0.0009 moles

Moles HCl = 0.025 M * 0.035 L = 0.000875 moles

Moles NH4+ = 0 moles

Number of moles at the equilibrium:

Moles NH3 = 0.0009 -0.000875 =0.000025 moles

Moles HCl = 0

Moles NH4+ = 0.000875 moles

Concentration at the equilibrium:

[NH3]= 0.000025 moles / 0.065 L = 3.85*10^-4M

[NH4+] = 0.000875 M / 0.065 L = 0.0135 M

pOH = pKb + log [NH4+]/[NH3]

pOH =  4.75 + log (0.0135/3.85*10^-4)

pOH = 6.29

pH = 14 - 6.29 = 7.71

Step 5: adding 36 mL HCl

Calculate numbers of moles:

Moles of NH3 = 0.030 M * 0.030 L = 0.0009 moles

Moles HCl = 0.025 M * 0.036 L = 0.0009 moles

Moles NH4+ = 0 moles

Number of moles at the equilibrium:

Moles NH3 = 0.0009 -0.0009 =0 moles

Moles HCl = 0

Moles NH4+ = 0.0009 moles

[NH4+] = 0.0009 moles / 0.066 L = 0.0136 M

Kw = Ka * Kb

Ka = 10^-14 / 1.8*10^-5

Ka = 5.6 * 10^-10

Ka = [NH3][H3O+] / [NH4+]

Ka =5.6 * 10^-10 =  x² / 0.0136

x = 2.76 * 10^-6 = [H3O+]

pH = -log(2.76 * 10^-6)

pH = 5.56

Step 6: Adding 37 mL of HCl

Calculate numbers of moles:

Moles of NH3 = 0.030 M * 0.030 L = 0.0009 moles

Moles HCl = 0.025 M * 0.037 L = 0.000925 moles

Moles NH4+ = 0 moles

Number of moles at the equilibrium:

Moles NH3 = 0.0009 -0.000925 =0 moles

Moles HCl = 0.000025 moles

Concentration of HCl = 0.000025 moles / 0.067 L = 3.73 * 10^-4 M

pH = -log 3.73*10^-4= 3.43

The pH of the solution in the titration of 30 mL of 0.030 M NH₃ with 0.025 M HCl, is:

a) pH = 10.86

b) pH = 9.66

c) pH = 9.15

d) pH = 7.70

e) pH = 5.56

f) pH = 3.43          

     

Calculating the pH a) 0 mL        

Initially, the pH of the solution is given by the dissociation of NH₃ in water.  

NH₃ + H₂O ⇄ NH₄⁺ + OH⁻     (1)

The constant of the above reaction is:

[tex] Kb = \frac{[NH_{4}^{+}][OH^{-}]}{[NH_{3}]} = 1.76\cdot 10^{-5} [/tex]   (2)

At the equilibrium, we have:  

   NH₃    +    H₂O   ⇄   NH₄⁺    +    OH⁻     (3)  

0.030 M - x                      x               x

[tex] 1.76\cdot 10^{-5}*(0.030 - x) - x^{2} = 0 [/tex]

After solving for x and taking the positive value:

x = 7.18x10⁻⁴ = [OH⁻]  

Now, we can calculate the pH of the solution as follows:

[tex] pH = 14 - pOH = 14 + log(7.18\cdot 10^{-4}) = 10.86 [/tex]

Hence, the initial pH is 10.86.

   

b) 10 mL

After the addition of HCl, the following reaction takes place:

NH₃ + HCl ⇄ NH₄⁺ + Cl⁻  (4)  

We can calculate the pH of the solution from the equilibrium reaction (3).            

[tex] 1.76\cdot 10^{-5}(Cb - x) - (Ca + x)*x = 0 [/tex] (5)  

Finding the number of moles of NH₃ and NH₄⁺

The number of moles of NH₃ (nb) and NH₄⁺ (na) are given by:

[tex] n_{b} = n_{i} - n_{HCl} [/tex]     (6)

[tex] n_{b} = 0.030 mol/L*0.030 L - 0.025 mol/L*0.010 L = 6.5\cdot 10^{-4} moles [/tex]          

[tex] n_{a} = n_{HCl} [/tex]   (7)

[tex] n_{a} = 0.025 mol/L*0.010 L = 2.5 \cdot 10^{-4} moles [/tex]

Calculating the concentrations of NH₃ and NH₄⁺

The concentrations are given by:

[tex] Cb = \frac{6.5\cdot 10^{-4} moles}{(0.030 L + 0.010 L)} = 0.0163 M [/tex]   (8)

[tex] Ca = \frac{2.5 \cdot 10^{-4} mole}{(0.030 L + 0.010 L)} = 6.25 \cdot 10^{-3} M [/tex]      (9)

Calculating the pH

After entering the values of Ca and Cb into equation (5) and solving for x, we have:  

[tex] 1.76\cdot 10^{-5}(0.0163 - x) - (6.25 \cdot 10^{-3} + x)*x = 0 [/tex]

x = 4.54x10⁻⁵ = [OH⁻]

Then, the pH is:

[tex] pH = 14 + log(4.54\cdot 10^{-5}) = 9.66 [/tex]

Hence, the pH is 9.66.

c) 20 mL  

We can find the pH of the solution from the reaction of equilibrium (3).

 Calculating the concentrations of NH₃ and NH₄⁺

The concentrations are (eq 8 and 9):

[tex] Cb = \frac{0.030 mol/L*0.030 L - 0.025 mol/L*0.020 L}{(0.030 L + 0.020 L)} = 8.0\cdot 10^{-3} M [/tex]    

[tex] Ca = \frac{0.025 mol/L*0.020 L}{(0.030 L + 0.020 L)} = 0.01 M [/tex]    

Calculating the pH  

After solving the equation (5) for x, we have:

[tex] 1.76\cdot 10^{-5}(8.0\cdot 10^{-3} - x) - (0.01 + x)*x = 0 [/tex]

x = 1.40x10⁻⁵ = [OH⁻]

Then, the pH is:  

[tex] pH = 14 + log(1.40\cdot 10^{-5}) = 9.15 [/tex]

So, the pH is 9.15.

d) 35 mL

We can find the pH of the solution from reaction (3).

  Calculating the concentrations of NH₃ and NH₄⁺

[tex] Cb = \frac{0.030 mol/L*0.030 L - 0.025 mol/L*0.035 L}{(0.030 L + 0.035 L)} = 3.85\cdot 10^{-4} M [/tex]      

[tex] Ca = \frac{0.025 mol/L*0.035 L}{(0.030 L + 0.035 L)} = 0.0135 M [/tex]      

Calculating the pH  

After solving the equation (5) for x, we have:

[tex] 1.76\cdot 10^{-5}(3.85\cdot 10^{-4} - x) - (0.0135 + x)*x = 0 [/tex]

x = 5.013x10⁻⁷ = [OH⁻]      

Then, the pH is:  

[tex] pH = 14 + log(5.013\cdot 10^{-7}) = 7.70 [/tex]  

So, the pH is 7.70.

e) 36 mL  Finding the number of moles of NH₃ and NH₄⁺

[tex] n_{b} = 0.030 mol/L*0.030 L - 0.025 mol/L*0.036 L = 0 [/tex]    

[tex] n_{a} = 0.025 mol/L*0.036 L = 9.0 \cdot 10^{-4} moles [/tex]

                                   

Since all the NH₃ reacts with the HCl added, the pH of the solution is given by the dissociation reaction of the NH₄⁺ produced in water.

At the equilibrium, we have:                

NH₄⁺    +    H₂O   ⇄   NH₃    +    H₃O⁺

Ca - x                             x               x

[tex] Ka = \frac{x^{2}}{Ca - x} [/tex]  

[tex] Ka(Ca - x) - x^{2} = 0 [/tex]   (10)          

 

Calculating the acid constant of NH₄⁺

We can find the acid constant as follows:

[tex] Kw = Ka*Kb [/tex]

Where Kw is the constant of water = 10⁻¹⁴

[tex] Ka = \frac{1\cdot 10^{-14}}{1.76 \cdot 10^{-5}} = 5.68 \cdot 10^{-10} [/tex]  

Calculating the pH  

The concentration of NH₄⁺ is:

[tex] Ca = \frac{9.0 \cdot 10^{-4} moles}{(0.030 L + 0.036 L)} = 0.0136 M [/tex]      

After solving the equation (10) for x, we have:

x = 2.78x10⁻⁶ = [H₃O⁺]

Then, the pH is:  

[tex] pH = -log(H_{3}O^{+}) = -log(2.78\cdot 10^{-6}) = 5.56 [/tex]

Hence, the pH is 5.56.

f) 37 mL

Now, the pH is given by the concentration of HCl that remain in solution after reacting with NH₃ (HCl is in excess).

Calculating the concentration of HCl  

[tex] C_{HCl} = \frac{0.025 mol/L*0.037 L - 0.030 mol/L*0.030 L}{(0.030 L + 0.037 L)} = 3.73 \cdot 10^{-4} M = [H_{3}O^{+}] [/tex]      

Calculating the pH  

[tex] pH = -log(H_{3}O^{+}) = -log(3.73 \cdot 10^{-4}) = 3.43 [/tex]

Therefore, the pH is 3.43.

   

Find more about pH here:

brainly.com/question/491373

 

I hope it helps you!  

Chlorine can be prepared in the laboratory by the reaction of manganese dioxide with hydrochloric acid, HCl(aq) , as described by the chemical equation

MnO2(s)+4HCl(aq)⟶MnCl2(aq)+2H2O(l)+Cl2(g)

How much MnO2(s) should be added to excess HCl(aq) to obtain 185 mL Cl2(g) at 25 °C and 745 Torr ?

mass of MnO2:

Answers

Answer:

0.605 g

Explanation:

MnO₂(s) + 4HCl(aq) ⟶ MnCl₂(aq) + 2H₂O(l) + Cl₂(g)

First we calculate how many Cl₂ moles need to be produced, using the PV=nRT formula:

P = 745 Torr ⇒ 745 / 760 = 0.980 atmV = 185 mL ⇒ 185 / 1000 = 0.185 Ln = ?R = 0.082 atm·L·mol⁻¹·K⁻¹T = 25 °C ⇒ 25 + 273.16 = 298.16 K

Inputting the data:

0.980 atm * 0.185 L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 298.16 Kn = 0.00696 mol

Then we convert 0.00696 moles of Cl₂ to MnO₂ moles:

0.00696 mol Cl₂ * [tex]\frac{1molMnO_2}{1molCl_2}[/tex] = 0.00696 mol MnO₂

Finally we convert 0.00696 moles of MnO₂ to grams, using its molar mass:

0.00696 mol MnO₂ * 86.94 g/mol = 0.605 g

The Bohr model of the atom explains why emission spectra are discrete. It could also be used to explain the photoelectric effect. Which is a correct explaination of the photoelectric effect according to the model

Answers

Answer:

photoelectric effect, phenomenon in which electrically charged particles are released from or within a material when it absorbs electromagnetic radiation. The effect is often defined as the ejection of electrons from a metal plate when light falls on it.

Under certain conditions, the substance mercury(II) oxide can be broken down to form mercury and oxygen. If 32.2 grams of mercury(II) oxide react to form 29.8 grams of mercury, how many grams of oxygen must simultaneously be formed

Answers

Explanation:

This is a decomposition reaction. Firstly, you will want to write the chemical equation out and balance it.

[tex]2Hg_2O->4Hg+O_2[/tex] (The -> is supposed to be an arrow, sorry!)

We see that there's only 1mol of Oxygen made in the products, we can do some simple math to solve for the amount of grams of Oxygen produced according to the amount of the reactant (Hg2O).

[tex]32.2gHg_2O*\frac{1molHg_2O}{417.18gHg_2O}*\frac{1molO_2}{2molHg_2O}*\frac{32gO_2}{1molO_2}[/tex]

I want to break this down, just in case:

The 417.18gHg2O is the molecular mass of the molecule (so I doubled Hg and added 16 to it to get this number).

As we can see in the chemical equation, 1mol Hg2O produces 2mol O because Oxygen is a diatomic molecule (so there will always be two of it when it's by itself).

And finally, in 1mol O2 there are 32g of O2.

** When you do math like this, always make sure that all of your units cancel out except for the units you're looking for. For example, here we're looking for the grams of Oxygen, so after everything else cancels out, we should only have grams O2.

So, 1.23gO2 should be your answer.

calculate the molarity in a 0.550 m solution of NaCl in water. Assume that the solution density is 1.03g/mol

Answers

Answer:

M=0.549M

Explanation:

Hello there!

In this case, according to the given information, it turns out possible for us to perform this calculation by firstly assuming we have 1 kg of water as the solvent so that we have 0.550 moles of NaCl as well. Moreover, we realize we have 1000 grams of water and the correct mass of the solution can be calculated by converting 0.550 moles of NaCl to grams by using its molar mass:

[tex]m_{solute}=0.550mol*\frac{58.44 g}{1mol}= 32.14g\\\\m_{solution}=1000g+32.14g=1032.14g[/tex]

And subsequently, the volume in liters by using the density and the correct conversion factor:

[tex]V_{solution}=1032.14g*\frac{1mL}{1.03g} *\frac{1L}{1000mL} =1.002L[/tex]

Finally, the molarity will be:

[tex]M=\frac{0.550mol}{1.002L} =0.549M[/tex]

Regards!

If 0.250 L of a 5.90 M HNO₃ solution is diluted to 2.00 L, what is the molarity of the new solution?

Answers

Answer:

0.74 M

Explanation:

From the question given above, the following data were obtained:

Molarity of stock solution (M₁) = 5.90 M

Volume of stock solution (V₁) = 0.250 L

Volume of diluted solution (V₂) = 2 L

Molarity of diluted solution (M₂) =?

The molarity of the diluted solution can be obtained by using the dilution formula as illustrated below:

M₁V₁ = M₂V₂

5.90 × 0.250 = M₂ × 2

1.475 = M₂ × 2

Divide both side by 2

M₂ = 1.475 / 2

M₂ = 0.74 M

Thus, the molarity of the diluted solution is 0.74 M

In the context of small molecules with similar molar masses, arrange the intermolecular forces by strength.

a. London dispersion forces
b. hydrogen bonding
c. dipole-dipole interactions

Answers

Answer:

Hydrogen bonding - London dispersion forces - dipole-dipole interactions

Strongest ----> Weakest

what class of organic compound is formed when cyclopentanone reacts with ethylamine in the presence of trace acid

Answers

The question is incomplete, the complete question is;

What functional group results when cyclopentanone reacts with ethylamine in the presence of trace acid? A) cyanohydrin B) semicarbazone C) imine D) enamine E) oxime

Answer:

imine

Explanation:

An imine is an unsaturated amine. An imine contains the carbon- nitrogen double bond.

Imines are obtained when a carbonyl compound is condensed with NH3 or an amine. The reaction involves several steps in its mechanism.

Since cyclopentanone is a ketone (carbonyl compound) and ethylamine is an amine,in the presence of trace acid, condensation of the two compounds occur to yield an imine

In an endothermic reaction, reactants are __ products.
equal to
less stable than
more stable than
equally stable than

Answers

C) more stable than
I think

Calcium chloride and magnesium sulfate are common drying agents. What type of solvent should be dried with calcium chloride, and what type with magnesium sulfate

Answers

Answer: The type of solvent that should be dried with calcium chloride is esters while magnesium sulfate is diethyl ether

Explanation:

Drying agents are mainly hygroscopic substances that has the ability to absorb water on exposure to the atmosphere but not enough to form solutions. They are used in desiccators. Examples of drying agents include:

--> CALCIUM CHLORIDE: This is a compound of calcium that is found in soil water and sea water. It is prepared by the action of dilute hydrochloric acid on calcium trioxocarbonate(IV). The anhydrous salt is used in drying a wide variety of solvent including esters.

--> MAGNESIUM SULFATE: This is a slightly acidic drying agent. It works well in solvents like diethyl ether. It is a fast drying agent because it comes as a fine powder with a large surface area.

which straight-chain alkane would you predict to be the most viscous? all are liquids exhbiting the general bonding pattern ch3-(ch2)n-ch3

Answers

The question is incomplete, the complete question his;

Which straight chain alkane below would you predict to be the most viscous? Why? All are liquids exhibiting the general bonding pattern CH3-(CH2)n-CH3

C9H20

C10H22

C5H12

C6H14

C12H26

Answer:

C12H26

Explanation:

Generally, the viscosity of a liquid increases with increase in molecular mass of the substance.

Liquids of high molecular mass do not flow easily. This means that they posses high viscosity.

Thus, since C12H26 has the highest molecular mass among the options given in the question, C12H26 exhibits the greatest viscosity.

During a reaction, ΔH for reactants is −750 kJ/mol and ΔH for products is 920 kJ/mol. Which statement is correct about the reaction? (5 points)

Group of answer choices

It is endothermic because the energy required to break bonds in the reactants is less than the energy released when the products are formed.

It is endothermic because the energy required to break bonds in the reactants is greater than the energy released when the products are formed.

It is exothermic because the energy required to break bonds in the reactants is less than the energy released when the products are formed.

It is exothermic because the energy required to break bonds in the reactants is greater than the energy released when the products are formed.

Answers

Answer: The statement it is endothermic because the energy required to break bonds in the reactants is less than the energy released when the products are formed, is true.

Explanation:

A chemical reaction in which heat energy  is released is called an exothermic reaction. For exothermic reactions, the value of [tex]\Delta H[/tex] is always negative.

A chemical reaction in which heat energy is absorbed is called an endothermic reaction. For endothermic reaction, the value of [tex]\Delta H[/tex] is always positive.

In endothermic reactions, energy required for breaking the bonds between reactants is less than the energy when products are formed due to which the value of [tex]\Delta H[/tex] remains positive.

Thus, we can conclude that the statement it is endothermic because the energy required to break bonds in the reactants is less than the energy released when the products are formed, is true.

It is endothermic because the energy required to break bonds in the reactants is greater than the energy released when the products are formed. The correct option is B.

The above reaction is endothermic because more energy is produced when new bonds form in the products (H = 920 kJ/mol) than is required to break bonds in the reactants (H = -750 kJ/mol).

In an endothermic process, more energy than is generated during bond creation is absorbed from the environment to dissolve existing bonds. This causes a net absorption of energy, which cools the system.

The reaction takes more energy than it releases, proving its endothermic nature, as seen by the positive difference between the energy needed to dissolve bonds and the energy released during bond formation.

Thus, the correct option is B.

For more details regarding endothermic process, visit:

https://brainly.com/question/28909381

#SPJ3

Your question seems incomplete, the probable complete question is:

During a reaction, ΔH for reactants is −750 kJ/mol and ΔH for products is 920 kJ/mol. Which statement is correct about the reaction? (5 points)

Group of answer choices

A. It is endothermic because the energy required to break bonds in the reactants is less than the energy released when the products are formed.

B. It is endothermic because the energy required to break bonds in the reactants is greater than the energy released when the products are formed.

C. It is exothermic because the energy required to break bonds in the reactants is less than the energy released when the products are formed.

D. It is exothermic because the energy required to break bonds in the reactants is greater than the energy released when the products are formed.

formula of
Al³⁺ and SO₄²⁻

Answers

Answer:

The formula of Al³⁺ and SO₄²⁻ is aluminum sulfate.

Explanation:

The formula for aluminum sulfate is Al₂(SO₄)₃. If we say in terms of ions. The ions are Al³⁺. It is a positive ion or the cation. Other ion is SO₄²⁻. It is sulfate ion. It is anion.

Aluminum sulphate is used in water purification and as a mordant in dyeing and printing textiles.

Hence, the formula of Al³⁺ and SO₄²⁻ is aluminum sulfate.

Other Questions
Which of the ice giants have all of these characteristics: less distinct bands and zones than the gas giants; spin axis inclination within a few degrees; rings; shorter-lived storms than gas giants; orbital inclination within a few degrees of Earth check all that apply. sec theta is undefinded for theta = ____ . A. pi/2B.0 C. pi D.3pi/2 we have to create social awareness to fight against corruption.(Negative) Unit sales for new product ABC have varied in the first seven months of this year as follows: Month Jan Feb Mar Apr May Jun Jul Unit Sales 148 329 491 167 228 285 441 What is the (population) standard deviation of the data in a two digit number the tens digit is 6 more than the units digit. if the digits are interchanged, the sum of the new and the original number is 132. Determine the original number. what the volume of a sphere with a diameter of 21.4 dm? How is mathematical thinking established? How can we have mathematical thinking? In your own words, explain how the precise timing of an element's radioactive decay helps scientists find the actual age of a material? (5 points) State any two ideas philosophers that you consider to be the most important for society to function effectively A 75-year-old man in long term care. He has been bed bound for longer than six months. His history shows he has cardiac and circulatory problems, exacerbated by his lack of activity. Explain some proactive changes staff might make for this gentleman that will enhance his health. Support your answer using specific facts, data, examples, and other information drawn from the textbook and at least one other supplemental source. will give brainyest (m^2/3 n^-1/3)^6 Discuss the impact of development planning for economic development for a development country like Pakistan under what circumstances a country should go for short term medium term and long term plan (it is a economics question) The Marked price, inclusive of GST, of a notebook computer is $1679.90.it is sold at a discount of 10%.a) find its marked price before GSTb)Find the GST before discount.c)What is the selling price of the computer d) find the GST after the discounte)what is the percentage decrease in the GST x-7x+5 in the form (x-a)-b What was the main function of George Creefs four-minute men? Question 1: Use the image and your knowledge of the isosceles triangle to find the value of x Help meeee plzzzzzz!!!! Q2a). State TWO (2) assumptions of using the Rational method for computing runoff. b). Explain eachof the following terms in relation to determining storm runoff. i. Time of concentration ii. Runoff coefficient iii. Return period c).With the aid of a sketch, explain a hydrograph. Pls help me with thisFreedom by Langston HughesFreedom will not comeToday, this yearNor everThrough compromise and fear.I have as much rightAs the other fellow hasTo standOn my two feetAnd own the land.I tire so of hearing people say,Let things take their course.Tomorrow is another day.I do not need my freedom when Im dead.I cannot live on tomorrows bread.FreedomIs a strong seedPlantedIn a great need.I live here, too.I want my freedomJust as you.How is the poem organized? Where do the shifts come? Read the excerpt from Birches by Robert Frost. When I see birches bend to left and right Across the line of straighter darker trees, I like to think some boys been swinging them.But swinging doesnt bend them down to stay. Ice-storms do that. Often you must have seen themLoaded with ice a sunny winter morning After a rain. They click upon themselves As the breeze rises, and turn many-colored As the stir cracks and crazes their enamel. Soon the suns warmth makes them shed crystal shells Shattering and avalanching on the snow-crust Such heaps of broken glass to sweep away Youd think the inner dome of heaven had fallen.Which lines describe the ice wrapping the tree branches?As the breeze rises, and turn many-colored As the stir cracks and crazes their enamel. Soon the suns warmth makes them shed crystal shells Shattering and avalanching on the snow-crustBut swinging doesnt bend them down to stay. Ice-storms do that. Often you must have seen themSuch heaps of broken glass to sweep away Youd think the inner dome of heaven had fallen. Mark this and return Next