Answer the following questions: (Questions about titration)
a. Why is it important to keep the NaOH solution covered at all times?
b. How will the molarity of NaOH solution be affected by its continued exposure to the atmosphere?
c. The pale pink color of the titration solution at the end point will fade to colorless after several minutes when exposed to the atmosphere. Account for this color change.
d. What volume (in mL) of 0.293 M Ba(OH)2 is required to neutralize 25.00 mL of 0.200M HNO3?

Answers

Answer 1

Answer:

Following are the solution to the given question:

Explanation:

For question a:

It is prevented that the atmospheric [tex]CO_2[/tex] through dissolving in the solution and make carbonic acid [tex](H_2CO_3)[/tex] which reacts with the [tex]NaOH:[/tex]

[tex]CO_2+ H_20\to H_2CO_3\\\\H_2CO_3 + NaOH \to NaHCO_3 +H_2O\\\\H_2CO_3 + 2 NaOH \to Na_2CO_3 + 2H_2O\\\\[/tex]

For question b:

For this, the [tex]NaOH[/tex] reacts with the dissolved [tex]CO_2[/tex]  so, the molarity of the [tex]NaOH[/tex] will be decreased.

For question C:

In this, the Phenolphthalein is pink in the basic solution[tex](high \ pH)[/tex] and colorless throughout the acidic solution[tex](low\ pH)[/tex].

if the solution is exposed  from the atmosphere, the [tex]CO_2[/tex] is from the air dissolving in the solution, and making the [tex]H_2CO_3[/tex] that gives the [tex]H^{+}\ ions[/tex]

[tex]\to[/tex] lower pH.

[tex]\to[/tex] colorless phenolphthalein  

For question D:

[tex]Ba(OH)_2 + 2 HNO_3 \to Ba(NO_3)_2+ 2H_2O\\\\[/tex]

Calculating the moles of[tex]HNO_3 = volume \times \text{concentration of} HNO_3\\\\[/tex]

                                                      [tex]= \frac{25}{1000} \times 0.200\\\\= 0.005\ mol\\\\[/tex]

Calculating the moles of  [tex]Ba(OH)_2= \frac{1}{2} \times\text{moles of}\ HNO_3\\\\[/tex]

                                [tex]=\frac{1}{2} \times 0.005\\\\= 0.0025 \ mol\\\\[/tex]

Calculating the volume of [tex]Ba(OH)_2=\frac{moles}{concentration\ of\ Ba(OH)_2}[/tex]

                                   [tex]=\frac{0.0025}{0.0293}\\\\=0.08532\ L\\\\= 85.32 \ mL\\\\= 85.3\ mL[/tex]


Related Questions

What is the formula of the compound Pentasilicon trioxide ?

Answers

Answer: the molecular formula of  trioxide is ClOClO3 or Cl2O4

hope its helps you.

keep smiling be happy stay safe

An aqueous solution contains 0.29 M of benzoic acid (HA) and 0.16 M of sodium benzoate (A-). If the pH of this solution was measured to be 4.63, calculate the pKa of benzoic acid g

Answers

Answer:

pKa = 4.89.

Explanation:

We can solve this problem by using the Henderson-Hasselbach equation, which states:

pH = pKa + log [tex]\frac{[A^-]}{[HA]}[/tex]

In this case [A⁻] is the concentration of sodium benzoate and [HA] is the concentration of benzoic acid.

We input the given data:

4.63 = pKa + log [tex]\frac{0.16}{0.29}[/tex]

And solve for pKa:

pKa = 4.89

Many home barbeques are fueled with propane gas (C3H8)(C3H8). Part A What mass of carbon dioxide is produced upon the complete combustion of 27.9 LL of propane (the approximate contents of one 5-gallon tank)

Answers

Answer:

41264 g of CO₂

Explanation:

Combustion reaction is:

C₃H₈ + 5O₂ →  3CO₂  +  4H₂O

1 mol of propane react to 5 moles of oxygen in order to proudce 3 moles of carbon dioxide and 4 moles of water.

In a combustion reaction, our reactant reacts to oxygen and the products are always CO₂ and water.

We have the volume of propane but we need moles of it, so we need to apply density.

Density = mass / volume so mass = density . volume.

Density of propane is: 493 g/L

Mass of propane is 493 g/L . 27.9L = 13754.7 g

We convert mass to moles: 13754.7 g . 1 mol/ 44g = 312.6 moles

According to reaction, 1 mol of propane can produce 3 moles of CO₂

Our 312.6 moles will produce 312.6 . 3 = 937.8 moles

We convert moles to mass: 937.8 mol . 44 g/mol = 41264 g

refer to pic plssss

Answers

Answer:

fgufyifyifyiyduhyufyiddjyfjyf86yif

what is the qualitative analysis of (nh4) 2co3 using NaOH, HCL, BaCL2, and AgNO3​

Answers

Answer:

qualatatiev is fs-hj_jakakak

Which elements are main-group elements?
1. Te
2. K
3. V
4. Re
5. Ag

Answers

Answer:

Te

K

Explanation:

Main group elements are elements designated and located on the s-block and p-block on the periodic table. The core group or prominent elements are the elements that make up those groups. These groupings comprise the most naturally rich and abundant elements. The main group elements are those whose characteristics are more predicted as a function of their periodic table location. From the given options, only Te and K are elements of the main-group.

Each of the following sets of quantum numbers is supposed to specify an orbital. Choose the one set of quantum numbers that does NOT contain an error.

a. n = 4, l = 3, ml =-4
b. n = 2, l = 2, ml =0
c. n = 3, l = 2, ml =-2
d. n = 2, l = 2, ml =+1

Answers

Answer:

n = 3, l = 2, ml =-2

Explanation:

Quantum numbers are a set of values which can be used to describe the energy and position of an electron in space.

There are four sets of quantum numbers;

1) principal quantum number

2) orbital quantum number

3) spin quantum number

4) magnetic quantum number.

The values of orbital quantum number include; -l to +l;

The set of quantum numbers without error is ; n = 3, l = 2, ml =-2

What is the amount of solute required if the solution is 50 ml and the solvent is 35 ml. Solve and explain

I don’t know what to do

Answers

Answer:

15 mL of the solute

Explanation:

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

Solution = 50 mL

Solvent = 35 mL

Solute =?

Solution is simply defined as:

Solution = solute + solvent

With the above formula, we can easily obtain the solute in the solution as follow:

Solution = 50 mL

Solvent = 35 mL

Solute =?

Solution = solute + solvent.

50 = solute + 35

Collect like terms

50 – 35 = solute

15 = solute

Solute = 15 mL

Therefore, 15 mL of the solute is required.

Liquid A is poured into Liquid B and a single, clear layer results. More Liquid A is added and two distinct layers form. The solution is now_____and there is a_____equilibria occurring.

Answers

Answer:

Explanation:

Liquid A is poured into Liquid B and a single, clear layer results. More Liquid A is added and two distinct layers form. The solution is now unsaturated and there is a static equilibria occurring

Element X has two naturally occurring isotopes, 35X and 36X . 35X has a percent natural abundance of 30%, while 36X has a percent natural abundance of 70%. What is the average atomic mass of element X

Answers

Answer:

= 35.7 amu

Explanation:

            Isotopic                fractional                                Wt Avg mass

          mass (amu)      abundance (= % / 100)       = Isotopic mass X (= % / 100)

X-35          35                         0.30                                           10.5 amu

X-36          36                         0.70                                           25.2 amu

__________________________________________________________

Average Atomic Mass of Element X = ∑ Wt. Avg. Masses = 35.7 amu

Write the balanced reaction for the methanol cannon demo that includes their Lewis structures . The reaction is the combustion of methanol (CH3OH). Include the states (s, l, g) in your balanced equation as well.

Answers

Answer:

The reaction is the combustion of methanol (CH3OH).

Write the balanced chemical equation.

Draw Lewis structures for each structure.

Explanation:

The balanced chemical equation for the combustion of methane is shown below:

[tex]2CH_3OH(g)+3O_2(g)->2CO_2(g)+ 4 H_2O(g)[/tex]

Lewis structures of the given molecules are shown below:

What would you expect to observe when Br2 reacts with 2-butyne?

Answers

Answer:

I expect to observe a change in colour from reddish brown to a colourless solution

Explanation:

Bromine (Br2) attacks the electron rich carbon-carbon triple bond in but-2-yne, an alkyne to form an initial product 2, 3 dibromobut-2-ene; which reacts with excess bromine to form a final product 2,2,3,3 -tetrabromobutane.

The reaction occurs in two steps. On approaching but-2-yne, bromine molecule becomes polarised forming an induced dipole containing a bromonium ion.

Br - Br → Br+ - Br-

The bromonium ion (Br+) formed then attacks the carbon - carbon triple bond to form the initial product

2,3- dibromobut-2-ene

CH2-C≡C-CH2 + Br+ →

CH2 - CBr =CBr-CH2

(2,3- dibromobut-2-ene)

Which in the presence of excess bromine gives the final product

2,2,3,3 - tetrabromobutane.

CH2 - CBr =CBr-CH2 + Br2 →

CH3 -CBr2-CBr2 - CH3

2,2,3,3 - tetrabromobutane.

A visible change in colour from the reddish-brown colour of Bromine to a colourless solution is observed during the reaction.

What is the molecular formula of the structure below?

Picture is attached pls help I’ll mark as brainliest for the right answer

Answers

Answer:

C₆H₆

Explanation:

Each border of the figure represents 1 atom of carbon. We have 6 borders = 6 atoms of carbon.

Each atom of carbon form 4 bonds. All the carbons are doing a double bond and a single bond with other carbons. That means are bonded 3 times. The other bond (That is not represented in the figure. See the image) comes from hydrogens. As we have 6 carbons that are bonded each 1 with one hydrogen. There are six hydrogens and the molecular formula is:

C₆H₆

This structure is: Benzene

Indicate type of chemical reactions for 2Mgl2+MN(SO3)2=2MgSO3+Mnl4

Answers

Answer:

double decomposition reaction

How many moles are contained in .984 molecules F2?

Answers

Answer:

1.6 x 10⁻²⁴ moles

Explanation:

We have 0.984 molecules of F₂. We know that 1 mol is equal to 6.022 x 10²³ molecules. Thus, we have a conversion factor: 1 mol/6.022 x 10²³ molecules

So, we multiply the molecules of F₂ by the conversion factor to calculate the moles:

0.984 molecules x  1 mol/6.022 x 10²³ molecules = 1.6 x 10⁻²⁴ moles

What is determined by calculating the slope of the position versus time graph distance

Answers

Answer:

Determining the Slope on a p-t Graph. It was learned earlier in Lesson 3 that the slope of the line on a position versus time graph is equal to the velocity of the object. ... If the object has a velocity of 0 m/s, then the slope of the line will be 0 m/s. The slope of the line on a position versus time graph tells it all.

Explanation:

#carryonlearning

Determining the Slope on a p-t Graph. It was learned earlier in Lesson 3 that the slope of the line on a position versus time graph is equal to the velocity of the object. If the object is moving with a velocity of +4 m/s, then the slope of the line will be +4 m/s.

Which procedure could a student use to examine an intensive property of a rectangular block of wood
Find the mass.
Record the length. Measure the volume. Determine the density.

Answers

Answer:

density

Explanation:

The procedure that the student could use to examine an intensive property of a rectangular block of wood is to determine its density. Density is intensive because it is the ration between the mass and the volume.

Answer: find the mass option A

Explanation:

What is the volume of a flask containing 0.199mol of Cl2at a temperature of 313K and a pressure of 1.19atm

Answers

Answer:

43.0 L

Explanation:

Step 1: Given and required data

Moles of chlorine gas (n): 0.199 molTemperature (T): 313 KPressure (P): 1.19 atmIdeal gas constant (R): 0.0821 atm.L/mol.K

Step 2: Calculate the volume of the flask (V)

We will use the ideal gas equation.

P × V = n × R × T

V = n × R × T / P

V = 1.99 mol × (0.0821 atm.L/mol.K) × 313 K / 1.19 atm = 43.0 L

The answer is 4.30 L

Consider reaction AgCIO3(aq)+Mgl2(aq)

Answers

Answer:

the product is Mg(Clo3)2 + AgI

What volume in mL of 0.300 M NaF would be required to make a 0.0450 M solution of NaF when diluted to 250.0 mL with water?

Answers

Answer: A volume of 37.5 mL of 0.300 M NaF would be required to make a 0.0450 M solution of NaF when diluted to 250.0 mL with water.

Explanation:

Given: [tex]M_{1}[/tex] = 0.300 M,   [tex]V_{1}[/tex] = ?

[tex]M_{2}[/tex] = 0.0450 M,    [tex]V_{1}[/tex] = 250.0 mL

Formula used is as follows.

[tex]M_{1}V_{1} = M_{2}V_{2}[/tex]

Substitute the values into above formula as follows.

[tex]M_{1}V_{1} = M_{2}V_{2} \\0.300 M \times V_{1} = 0.0450 M \times 250.0 mL\\V_{1} = 37.5 mL[/tex]

Thus, we can conclude that a volume of 37.5 mL of 0.300 M NaF would be required to make a 0.0450 M solution of NaF when diluted to 250.0 mL with water.

give one important characteristic of the particles of matter very sort answer​ give

Answers

Answer:

The important characteristics of the particles of matter are – They are very, very small. They have spaces between them. They are constantly moving.

Answer:

They are very very small

What happens when Sulphur dioxide (so2) gas is passed through an acidified solution of hydrogen . sulfide (H₂S) gas : ​

Answers

Answer:

When SO

2

is passed through an acidified solution of H

2

S, sulphur is precipitated out according to the reaction.

2H

2

S+SO

2

→2H

2

O+3S

Identify the options below that are results of adding a catalyst to a chemical system.
The reaction rates are increased.
The reaction quotient is unaffected.
The reaction quotient decreases.
The equilibrium constant is unaffected.

Answers

Answer:

The correct options are a, b and d

Explanation:

A catalyst is a substance that increases the rate of a chemical reaction by reducing the activation energy. Le Catelier's  principle explains how a substance or an "action" can affect a reaction in equilibrium.

The principle states that when a change is made to the conditions of a reacting system at equilibrium, the position of the equilibrium moves to counteract the change made. These changes are change in temperature, pressure, volume and/or concentration. These changes will either cause the equilibrium to shift forward or backward.

However, the presence of a catalyst DOES NOT affect a chemical equilibrium/equilibrium constant nor does it affect the reaction quotient because the same amount of reactants and products are available just as in uncatalyzed reaction except that the reaction proceeds faster (which does not affect equilibrium).

The rate of reaction is given as the time required by the reactant to convert into the product. The addition of catalyst increases the rate of reaction, while the reaction quotient and the equilibrium remain unaffected.

What is a catalyst?

A catalyst is a chemical or compound that adds to the reaction and lowers the activation energy by providing an alternative path to the reaction.

The catalyst takes part in the reaction but did not consume in the chemical reaction.

The equilibrium and the reaction quotient are dependent on the conversion of the reactant to the product. The catalyst is not used in the reaction and thus did not affect the reaction quotient or the equilibrium.

Hence, options A, B, and D are correct for the use of catalysts in the chemical reaction.

Learn more about catalysts, here:

https://brainly.com/question/17052831

How many moles of
H
C
l
are in
44.1
mL
of a
1.26
M
H
C
l
solution?

Answers

Answer: There are 0.0556 moles present in 44.1 mL of a 1.26 M HCl solution.

Explanation:

Given: Volume = 44.1 mL (1 mL = 0.001 L) = 0.0441 L

Molarity = 1.26 M

Molarity is the number of moles of a substance present in liter of a solution.

Therefore, moles of HCl are calculated as follows.

[tex]Moles = \frac{moles}{Volume (in L)}\\1.26 M = \frac{moles}{0.0441 L}\\moles = 0.0556 mol[/tex]

Thus, we can conclude that there are 0.0556 moles present in 44.1 mL of a 1.26 M HCl solution.

Please can someone please help me !!

Answers

Answer:

False

Explanation:

A sample of gas is placed into an enclosed cylinder and fitted with a movable piston. Calculate the work (in joules) done by the gas if it expands from 5.33 L to 11.05 L against a pressure of 1.50 atm.

Answers

Explanation:

here is the answer. Feel free to ask for more chem help

How do forces between particles in gases compare to forces in the other states of matter?​

Answers

The forces in gases are weaker than forces in solids and liquids.

Because they have more kinetic energy that overcomes the force of attraction.

PLEASE HELP!!

How does temperature, agitation, and particle size affect solubility?

Answers

Answer:

At higher temperatures, particles move faster and collide more, increasing solubility rates.

Agitation increases solubility rates as well, by bringing fresh solvent into contact with the undissolved solute

The smaller the particle size, the higher (faster) solubility rate. Vice versa, the bigger the particle size, the lower (slower) solubility rate.

Explanation:

A. Consider the following neutral electron configurations in which n has a constant value. Which configuration would belong to the element with the most negative electron affinity, Eea?
1. 2s2
2. 2s2 2p2
3. 2s2 2p5
4. 2s2 2p6
B. Arrange the following elements from greatest to least tendency to accept an electron.
Rank from greatest to least tendency to accept an electron. To rank items as equivalent, overlap them.
1. Sr
2. Sn
3. Rb
4. Te
5. I

Answers

Answer:

2s2 2p5

Rb < Sr< Sn< Te<I

Explanation:

Electron affinity is the ability of an atom to accept electrons to form negative ions.

Electron affinity is a periodic trend that decreases down the group but increases across the period.

This accounts for the trends observed in the answer. The atom having the electronic configuration, 2s2 2p5 must be a halogen and it exhibits the highest value of electron affinity.

Also, since electron affinity increases across the period, the electron affinities of the elements increases. Therefore, the arrangement of atoms as shown in the answer depends on increasing electron affinity.

A chemist makes of nickel(II) chloride working solution by adding distilled water to of a stock solution of nickel(II) chloride in water.Calculate the concentration of the chemist's working solution. Round your answer to significant digits.

Answers

Answer:

0.0900 mol/L

Explanation:

A chemist makes 330. mL of nickel(II) chloride working solution by adding distilled water to 220. mL of a 0.135 mol/L stock solution of nickel(II) chloride in water. Calculate the concentration of the chemist's working solution. Round your answer to significant digits.

Step 1: Given data

Initial concentration (C₁): 0.135 mol/LInitial volume (V₁): 220. mLFinal concentration (C₂): ?Final volume (V₂): 330. mL

Step 2: Calculate the concentration of the final solution

We prepare a dilute solution from a concentrated one. We can calculate the concentration of the working solution using the dilution rule.

C₁ × V₁ = C₂ × V₂

C₂ = C₁ × V₁/V₂

C₂ = 0.135 mol/L × 220. mL/330. mL = 0.0900 mol/L

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