The mass of ammonium chloride that must be added is : ( A ) 4.7 g
Given data :
Volume of water ( V ) = 250 mL = 0.25 L
pH of solution = 4.85
Kb = 1.8 * 10⁻⁵
Kw = 10⁻¹⁴
Given that the dissolution of NH₄Cl gives NH₄⁺⁺ and Cl⁻ ions the equation is written as :
NH₄CI + H₂O ⇄ NH₃ + H₃O⁺
where conc of H₃O⁺
[ H₃O⁺ ] = [tex]\sqrt{Ka.C}[/tex] and Ka = Kw / Kb
∴ Ka = 5.56 * 10⁻¹⁰
Next step : Determine the concentration of H₃O⁺ in the solution
pH = - log [ H₃O⁺ ] = 4.85
∴ [ H₃O⁺ ] in the solution = 1.14125 * 10⁻⁵
Next step : Determine the concentration of NH₄CI in the solution
C = [ H₃O⁺ ]² / Ka
= ( 1.14125 * 10⁻⁵ )² / 5.56 * 10⁻¹⁰
= 0.359 mol / L
Determine the number of moles of NH₄CI in the solution
n = C . V
= 0.359 mol / L * 0.25 L = 0.08979 mole
Final step : determine the mass of ammonium chloride that must be added to 250 mL
mass = n * molar mass
= 0.08979 * 53.5 g/mol
= 4.80 g ≈ 4.7 grams
Therefore we can conclude that the mass of ammonium chloride that must be added is 4.7 g
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The store paid 4.50 for a book and sold it for $7.65.what is the profit as a percent of the cost to the store? A. 3. 15% b. 58.8% c. 70% d. 315%
Answer: This would be C.) 70%
Explanation:
Find the volume of 8 gram of oxygen gas
Which of the compounds, C4H10, BaSO4, Zn(CN)2, Al(OH)3, contain an anion with a -1 charge?
Answer:
b
Explanation:
OH and CN both have -1 charges
How do many types of cells, like bacteria, reproduce?
Answer:
cells like bacteria are bisexual so they split and their offspring is 100 percent like the parent and this process happens over and over
Explanation:
_265Hs--->_16O+_9Be=_____?
Answer:
265hs+24.464536b+16o
Explanation:
265hs+16o+9b(2.718282)
=265hs+16o+24.464536b
=265hs+24.464536b+16o
what is the result of collisions of particles with an object? *
A. pressure on the object
B. pressure away from the object
C. the object gets lighter
D. the object gets heavier
Answer:
Particle collisions cause pressure.
Explanation:
The fast motion of gas particles gives them a relatively large amount of kinetic energy. Recall that kinetic energy is the energy that an object possesses because of its motion. The particles of a gas move in straight-line motion until they collide with another particle or with one of the walls of its container.
What is a proofreading tip you should use to double check that your work is error free
How you can check to make sure your work is error-free is by:
Placing a ruler under each line as you are reading itIf you are able to, try checking your work when you are the most alert so it can be easier to track a mistakeTry to read it out loud if you are comfortable with thatYou can have a friend, family member, or teacher help read it and check over itThink about the common mistakes you makeIf your work is computer written then you can use a spell checker app such as GrammarlyRead over your work at least two or three timesHope this Helps
Seeds Roots Cones Stem Spores Leaves 1. Mongo 2. Moss 3. Ferns 4. Pine Tree 5. Guava 6. Mango 7. Coconut 8. Katakataka 9. Potato 10. Okra 14
The method of propagation of the given organisms is shown below:
1. Mongo ---> seeds
2. Moss ---> spores
3. Ferns ---> stem
4. Pine Tree ---> cones
5. Guava ---> seeds
6. Mango ---> seeds
7. Coconut ---> seeds
8. Katakataka ---> leaves
9. Potato ---> stem
10. Okra ---> seeds
Definition of reproductionRepr0duction is the process by which living organisms produce young ones of their kind.
Repr0duction can either involve two parents through the joining of male and female gametes to produce a zygote i.e. seeds in plants and embryo in animals or can involve only one parent and occurs through vegetative parts such as roots, stem, or leaves.
List of organisms and their propagation partsThe table below gives organisms and their propagation parts:
1. Mongo ---> seed
2. Moss ---> spores
3. Ferns ---> stem
4. Pine Tree ---> cones
5. Guava ---> seeds
6. Mango ---> seeds
7. Coconut ---> seeds
8. Katakataka ---> leaves
9. Potato ---> stem
10. Okra ---> seeds
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You have a block of an unknown metal. Which properties would be most helpful in determining what it is? If it could be
Fill in the blank for the following statement: ________ is the movement of rocks, sand, or materials from a place?
Answer:
Erosion.
Explanation:
It can be as small as a grain of sand or as large as a boulder. Sediment moves from one place to another through the process of erosion. Erosion is the removal and transportation of rock or soil. Erosion can move sediment through water, ice, or wind.
what will happen to a person who doesn't recognize authors and even citing proper sources?
it will be called verbatim plagiarism, also called direct plagiarism
In general, people of __ heritage will be the last to get
white hair.
Answer:
African?
Explanation:
Describe four characteristics of S-block elements
1. s block elements have spherical s orbital as
their outermost orbital.
2. Since s orbital can accommodate a maximum of 2 electrons, each one of these elements have 1 or two electrons.
3. These s electrons are lost very easily to form
monopositive ions by Isoing one electron in the
outermost orbital or dipositive ions by losing 2
electrons.
4. They have low ionisation potentials and low electronegativities.
5. They are good conductors of heat and electricity, excepting H2 and He.
6. They are silvery, shiny metallic substances, (with the exception of hydrogen and helium which gaseous nonmetals).
7. They are malleable and ductile, i.e., we can
make sheets and wires from them, (exception:
H2, He)
8. They readily form ionic salts with most nonmetals.
hope it helps plzzz mark as brainliest
The results of Rutherford's gold foil experiment gave him the evidence to conclude that the center of an atom was A) called the nucleus. B) neutral and relatively small. C) positively charged and relatively small. D) a densely packed area containing both positive and negative particles.
Answer:
c)
Explanation:
because alpha particles can go through it
A ramp is at an angle of elevation of 15° . The distance from the top of the ramp to the ground is 20 feet. What is the length of the ramp?
Answer:
Length of ramp = 77.27ft
Explanation:
Step 1 - Sketch a diagram
Make a line about 15 deg. above the horizontal x-axis. Draw the horizontal and vertical components to form a right triangle. See image if you don’t understand.
Step 2 - Label your diagram
Your triangle creates a 15 deg. angle with the x-axis and we know the vertical distance from the top of the ramp to the ground is 20 ft.
Step 3 - Use trig to make an equation and solve
SOH CAH TOA
I’m this problem we know the angle, know “opposite, and we are solving for the hypotenuse of the triangle. Therefore, it would be easiest to use SOH or sin(theta)= (opp./hyp.) Plug in the numbers and solve for the hypotenuse.
All work is shown in the attached image.
By titration, it is found that 73.3 mL of 0.175 M NaOH(aq) is needed to neutralize 25.0 mL of HCl(aq). Calculate the concentration of the HCl solution.
Answer:
0.5131M
Explanation:
NaOH(aq) + HCl(aq) — NaCl(aq) + H20(l)
Mole ratio of acid to base 1:1
(Ca × Va)/ (Cb × Vb) = Na/Nb
(0.175 × 73.3)/ (Cb × 25)= 1/1
12.8275= 25 × Cb
Cb= 12.8275/25
= 0.5131M
Heart, 5 stars, and Brainiest to first right answer!
Which climate condition is typically found in the tropics due to the interaction of the atmosphere and hydrosphere?
A.Dry with low humidity
B.Dry with high humidity
C.Wet with high humidity
D.Stormy with low humidity
Answer:
A- Dry with low humidity
Explanation:
The hydrosphere includes the water which is on the surface of the earth, below the ground and in the air.
On analyzing the climatic conditions in the tropics due to the interaction of the atmosphere and hydrosphere, the presence of water droplets in tropics is less resulting in less humidity and, thus the climatic condition is dry.
Therefore the climatic condition that is typically found in tropics due to interaction of the atmosphere and hydrosphere is dry with low humidity.
Hope this helps!
The lab stockroom has a bottle of Sulfuric acid labeled 15.5M. How many mL of water will you need to add to 5.41mL of the acid solution in order to get a concentration of 0.175M?
The volume of water needed to make the solution is 473.76 mL
We'll begin by calculating the volume of the diluted solution.
Molarity of stock solution (M₁) = 15.5 MVolume of stock solution needed (V₁) = 5.41 mL Molarity of diluted solution (M₂) = 0.175 MVolume of diluted solution (V₂) =?M₁V₁ = M₂V₂
15.5 × 5.41 = 0.175 × V₂
83.855 = 0.175 × V₂
Divide both side by 0.175
V₂ = 83.855 / 0.175
V₂ = 479.17 mL
Finally, we shall determine the volume of water needed.
Volume of stock solution needed (V₁) = 5.41 mLVolume of diluted solution (V₂) = 479.17 mLVolume of water =?Volume of water = V₂ – V₁
Volume of water = 479.17 – 5.41
Volume of water = 473.76 mL
Therefore, the volume of the water needed is 473.76 mL
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4. The new element Plainsmenium (Pe) was discovered in 2005 by Monte E. Rey
(who will receive his Nobel Prize in Chemistry in the year 2012). It has
three isotopes: Pe-184 (24.60%), Pe-185 (11.20%), and Pe-188 (64.20%).
What is its average atomic mass?
This is my answer
Explanation:
p=m/v
where:. p=density
m=mass
v=volume
p=F/A = Lim ∆F / ∆A
1 ATM=14.7 psi
= 1.013x10⁶ d/cm²
1 bar=10⁶ d/cm²
=10⁵ N/m2
Hope it helps to you goodluck
I'm not sure but that's the answer of my notebook like my answer please
I need help with this question.
The London forces designated as A are much weaker than the dipole- dipole interaction designated as B.
The intermolecular forces are interactions that exists between molecules of a substance in a particular state of matter. The nature of intermolecular forces in a substance greatly affect the properties of the substance.
We can see that A represents weak London forces while B represents dipole - dipole interactions. The London forces are very much weaker than the dipole - dipole interactions.
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I have experiment measuring sugar content with liquid what should can I say in future remarks I want three points please help
Answer:
Liquid sugar is the sugar you consume in liquid form from beverages like sugar sweetened soda. The sugar in beverages is often highly concentrated and easy to consume in large amounts without feeling full. Some examples of these drinks are fairly obvious, such as sodas and fruit punch.
true or false in a chemical reaction some of the atoms will be changed into different type of atoms
Answer:
It's false
Explanation:
Choose the correct interpretation for the statement below:
"Relative atomic mass of T is 2"
A) The mass of one mole of T is two.
B) The mass of one T atom is double compared to the mass of one carbon-12 atom.
C)Mole ratio of T atom to 1/12 of carbon-12 atom is two.
D)The ratio of the mass of one T atom to 1/12 of the mass of one carbon-12 atom is two.
Answer:
b
Explanation:
How Does being a doormat help a tree survive winter
Answer: Trees, like all plants, are alive and require nutrients to survive. ... This dormancy is what allows trees to survive the cold winter. During dormancy, a tree's metabolism, energy consumption, and growth all slow down significantly in order to endure the harsh season of winter when water and sunlight are more scarce
Explanation: mark me brainlest plz if this helped only !
Potassium hydrogen phthalate, KHP, is a monoprotic acid often used to standardize NaOH solutions. If 0.212 g of KHP are dissolved into 50.00 mL of water and titrated with 35.00 mL of NaOH, what is the molarity of NaOH. Molar mass of KHP
The molarity of the NaOH solution is 0.03 M
We'll begin by calculating the mole of the KHP
Mass = 0.212 g Molar mass = 204.22 g/mol Mole of KHP =?Mole = mass /molar mass
Mole of KHP = 0.212 / 204.22
Mole of KHP = 0.001 mole
Next, we shall determine the molarity of the KHP solution
Mole of KHP = 0.001 mole Volume = 50 mL = 50/1000 = 0.05 L Molarity of KHP =?Molarity = mole / Volume
Molarity of KHP = 0.001 / 0.05
Molarity of KHP = 0.02 M
Finally , we shall determine the molarity of the NaOH solution
KHP + NaOH —> NaPK + H₂O
From the balanced equation above,
The mole ratio of the acid, KHP (nA) = 1The mole ratio of base, NaOH (nB) = 1From the question given above, the following data were obtained:
Volume of acid, KHP (Va) = 50 mL Molarity of acid, KHP (Ma) = 0.02 M.Volume of base, NaOH (Vb) = 35 mL Molarity of base, NaOH (Mb) =?MaVa / MbVb = nA / nB
(0.02 × 50) / (Mb × 35) = 1
1 / (Mb × 35) = 1
Cross multiply
Mb × 35 = 1
Divide both side by 35
Mb = 1 / 35
Mb = 0.03 M
Thus, the molarity of the NaOH solution is 0.03 M
Complete question:
See attached photo
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3. Carbon dioxide gas lowers the amount of oxygen that enters the blood? True or false
Answer:
true
Explanation:
because carbon dioxide is dencer than oxygen therefore it displaces it
1. In a heterogeneous mixture, the substances
A. can be physically separated.
B. are chemically combined.
C. can only be separated through chemical
processes.
D. break down into new substances.
Please answer
3 moles of nitrogen and 5 moles of hydrogen react to form ammonia. Use the balanced equation below to determine which is the limiting reactant.
N2 + 3H2 --> 2NH3
Answer:
H₂ is the limiting reactant
Explanation:
Balanced equations demonstrate the ratios of all reactants and products in terms of the number of atoms/molecules or moles;
In the given reaction:
1 mol of N₂ reacts with 3 mol of H₂ to produce 2 mol of NH₃
So the ratio of N₂ to H₂ to NH₃ will be 1:3:2
If we have 3 moles of N₂, we can apply the ratio to find that it will react with 9 moles of H₂ (3× the moles of N₂) to produce 6 moles of NH₃ (2× the moles of N₂);
Similarly, if we have 5 moles of H₂, then applying the ratio, we find that ⁵/₃ or 1.66... moles of N₂ (¹/₃× the moles of H₂) react with 5 moles of H₂ to produce ¹⁰/₃ or 3.33... moles of NH₃ (²/₃× the moles of H₂);
In order for all of the 3 moles of N₂ to react, it would require 6 moles of H₂;
There is only 5 moles of H₂ available, meaning there will be an excess of N₂;
5 moles of H₂ will react with 1.66... moles of the N₂, leaving 1.33... or ⁴/₃ moles of N₂ unreacted;
If the N₂ is in excess, then the H₂ is limited (i.e. the limiting reactant)
A quantity of 1.922 g of methanol (CH3OH) was burned in a constant-volume bomb calorimeter. Consequently, the temperature of the water rose by 4.20 Ce … lsius. If the heat capacity of the bomb plus water was 10.4 kJ/degree Celsius, calculate the molar heat of combustion of methanol
The formula for calculating the amount of energy or heat released is:
ΔH = C ΔT
where ΔH is heat of combustion, C is heat capacity, while ΔT is change in temperature
ΔH = 8.69 kJ / °C * (5.14°C)
ΔH = 44.67 kJ
Then we calculate the moles of CH3OH which has molar mass of 32.04 g/mol:
moles = 1.922 / 32.04 = 0.05999 mol
SO the molar heat of combustion is:
ΔHm = 44.67 kJ / 0.0599875 mol
ΔHm = 744.60 kJ / mol
the empirical mass is a whole number multiple of the molar mass true or false?
Answer:
True
Explanation: