As part of a soil analysis on a plot of land, a scientist wants to determine the ammonium content using gravimetric analysis with sodium tetraphenylborate, Na+B(C6H5)−4. Unfortunately, the amount of potassium, which also precipitates with sodium tetraphenylborate, is non‑negligible and must be accounted for in the analysis. Assume that all potassium in the soil is present as K2CO3 and all ammonium is present as NH4Cl.
A 5.025 g soil sample was dissolved to give 0.500 L of solution. A 100.0 mL aliquot was acidified and excess sodium tetraphenylborate was added to precipitate both K+ K + and NH+4 ions completely.
Compound Formula mass
B(C6H5)−4+K+⟶KB(C6H5)4(s) KB(C6H5)4 358.33 g/mol
B(C6H5)−4+NH+4⟶NH4B(C6H5)4(s) NH4B(C6H5)4 337.27 g/mol
K2CO3 138.21 g/mol
NH4Cl 53.492 g/mol
The resulting precipitate amounted to 0.277 g. A new 200.0 mL aliquot of the original solution was made alkaline and heated to remove all of the NH+4 as NH3. The resulting solution was then acidified, and excess sodium tetraphenylborate was added to give 0.105 g of precipitate.
Find the mass percentages of NH4Cl and K2CO3 in the original solid.
______ %NH4CL
______ %K2CO3

Answers

Answer 1

Answer:

Mass percentage of NH₄Cl = 3.54%

Mass percentage of K₂CO₃ = 1.01%

Explanation:

If a 200.0 mL aliquot produced  0.105 g of KB(C₆H₅)₄, then a 100.0 mL aliquot would produce 1/2 * 0.105 g = 0.0525 g of KB(C₆H₅)₄.

Therefore, mass of NH₄B(C₆H₅)₄ in the 100.0 ml aliquot = (0.277 - 0.0525)g = 0.2245 g

Number of moles of NH₄B(C₆H₅)₄ in 0.2245 g = 0.2245 g/ 337.27 g/mol = 0.0006656 moles

In 500 ml solution, number of moles present = 0.0006656 * 500/100 = 0.003328 moles.

From equation of the reaction; mole ratio of  NH₄⁺ and NH₄B(C₆H₅)₄ = 1:1

Similarly, mole ratio of  NH₄⁺ and NH₄Cl = 1:1

Therefore, moles of NH₄Cl in 500 ml sample = 0.003328 moles

Mass of NH₄Cl  = 0.003328 mol * 53.492 g/mol = 0.178 g

Mass percentage of NH₄Cl = (0.178/5.025) * 100% = 3.54%

Number of moles of KB(C₆H₅)₄ in 0.105 g (precipitated from 200.0 ml aliquot) = 0.105 g/ 358.33 g/mol = 0.000293 moles

In 500 ml solution, number of moles present = 0.000293 * 500/200 = 0.0007326 moles.

From equation of the reaction; mole ratio of  K⁺ and KB(C₆H₅)₄ = 1:1

Similarly, mole ratio of  K⁺ and K₂CO₃ = 2:1

Therefore, moles of K₂CO₃ in 500 ml sample = 0.0007326/2 moles =  0.0003663 moles

Mass of  K₂CO₃ = 0.0003663 mol * 138.21 g/mol = 0.05063 g

Mass percentage of K₂CO₃ = (0.05063/5.025) * 100% = 1.01%


Related Questions

What is the density of aluminium? |

एल्यूमीतनयम का घनत्व कतना होता है?

A : 2.7 g/cm3 | 2.7 g/cm3

B : 3.7 g/cm3 | 3.7 g/cm3

C : 4.7 g/cm3 | 4.7 g/cm3

D : 5.7 g/cm3 | 5.7 g/cm3

Ans: A : 2.7 g/cm3 | 2.7 g/cm3​

Answers

Answer:

answer 2.7

Explanation:

a.2.7g/cm3

"During a chemical reaction, you must have the same amount of substance
on both sides of the quation" This statement is the definition for the *

Answers

Answer:

This statement is the definition of law of conservation of mass.

Explanation:

Law of conservation of mass:

According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.

This law was given by French chemist  Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.

For example:

In given photosynthesis reaction:

6CO₂ + 6H₂O   →   C₆H₁₂O₆ +  6O₂

there are six carbon atoms, eighteen oxygen atoms and twelve hydrogen atoms on the both side of equation so this reaction followed the law of conservation of mass.

Let us consider the general chemical reaction.

A   +   B    →      C

5g +  5g           10g

Which element requires the least amount of energy to remove the most loosely held electron from a gaseous atom in the ground state? 1. K 2. Kr 3. As 4.br

Answers

Answer:

K

Explanation:

According to the law of superposition, where would you find objects with an older relative age?

Answers

Answer:

The law of superposition states that each rock layer is older than the one above it.  So, the relative age of the rock or fossil in the rock is older if it is farther down in the rock layers.

Which properties of grains determine the texture of rocks? Check all that apply.

feel

pattern

color

shape

size


I will mark Brainlyest

Answers

Shape the correct answer

Answer:

color shape and size

Explanation:

When a solution containing 1.4000 g of Ba(NO3)2 and 2.4000 g of HSO3NH2 is boiled, a precipitate forms. One possible identity for this precipitate is Ba(SO3NH2)2.
a) Determine the limiting reagent for the balanced reaction, and then calculate the theoretical yield in moles.
b) Calculate the experimental molar mass if 1.6925 g of product were formed.

Answers

Answer:

See explanation for detailed solution

Explanation:

The balanced reaction equation is Ba(NO3)2 + 2HSO3NH2 → Ba(SO3NH2)2 + 2HNO3

Number of moles of Ba(NO3)2 = 1.4 g/ 261.337 g/mol = 5.36 × 10^-3 moles

From the reaction equation;

1 mole of Ba(NO3)2 yields 1 mole of Ba(SO3NH2)2

5.36 × 10^-3 moles of Ba(NO3)2 yields 5.36 × 10^-3 moles of Ba(SO3NH2)2

For HSO3NH2

Number of moles = 2.4g/97.10 g/mol =0.0247 moles

2 moles of HSO3NH2 yields 1 mole of Ba(SO3NH2)2

0.0247 moles of HSO3NH2 yields 0.0247 ×1/2 = 0.0137 moles

Hence, Ba(NO3)2 is the limiting reactant

The theoretical yield of Ba(SO3NH2)2 is 5.36 × 10^-3 moles × 329.4986 g/mol = 1.766 g

b)

Number of moles = mass/ molar mass

Molar mass = mass/ number of moles

Molar mass = 1.6925 g/5.36 × 10^-3 moles = 315.76 g

The mass of 1 gram:

is kept as a standard platinum cylinder in France
equals 1 cm³
is .01 kg
equals the mass of 1 mL of water at 4°C

Answers

Answer:

C. equals the mass of 1 mL of water at 4°C

Explanation:

Which of the following is not a size-independent property of matter?
O volume
O boiling point
O state of matter
O conductivity

Answers

Answer:

the answer is D

Explanation:

hope it helps

The temperature at which a liquid becomes a gas is the
point.
O A) freezing
O B) boiling
O C) condensation
O D) melting

Answers

Answer:

Boiling

Explanation:

Lollll I need help with this question

Answers

Answer:

Waves are any vibration that transfers energy from place to place.

Explanation:

IM NOT SURE ABOUT THE VIBRATION BIT BUT I AM ABOUT THE ENERGY

Water is composed of one atom of oxygen and two atoms of

Answers

Answer:

Hydrogen.

Explanation:

You've probably seen "[tex]H_{2}0[/tex]" which is the formula for water. It means that there's 2 hydrogen atoms, and one oxygen atom, in one molecule of water.

Hope this helps! Feel free to mark me Brainliest if you feel this helped. :)

Answer:

the answer is H. (hydrogen)

Alison finds the total mass of a sample of baking soda, a balloon, and a glass container with vinegar in it. She adds the baking soda to the vinegar and immediately places the balloon over the mouth of the container.​

Answers

Answer:

The baking soda and vinegar react to create carbon dioxide, which inflates the balloon.

Explanation:

One differentiating characteristic between vascular and nonvascular plants is the lack of active transport structures in the nonvascular plants. How does the lack of xylem or phloem contribute to the smaller size of the nonvascular plants?

Nonvascular plants are smaller because xylem and phloem help a plant stand up taller.
Nonvascular plants have other transport structures that are microscopic and therefore take up less room.
Nonvascular plants rely upon concentration gradients to move food and water, which only works over small distances.
Nonvascular plants are smaller because they don’t photosynthesize as much as vascular plants and don’t get enough food.

Answers

Answer:

One of the most important characteristics of non-vascular plants is the absence of vascular tissues. Non-vascular plants do not have the vascular tissues known as xylem and phloem. ... As they do not have any vascular tissue, they cannot retain water for long time or transport it to other parts of the plant.

Explanation:

Answer:

fern

Explanation:

What is the frequency of a photon of light (in Hz) that has an energy of 2.50 x 10-18 J?

Answers

Answer:

The answer is

[tex]3.77 \times {10}^{15} \: \: \: Hz[/tex]

Explanation:

The frequency of the photon can be found by using the formula

[tex]f = \frac{E}{h} \\ [/tex]

where

E is the energy

f is the frequency

h is the Planck's constant which is

6.626 × 10-³⁴ Js

From the question

E = 2.50 × 10^-18 J

So we have

[tex]f = \frac{2.50 \times {10}^{ - 18} }{6.626 \times {10}^{ - 34} } \\ [/tex]

We have the final answer as

[tex]3.77 \times {10}^{15} \: \: \: Hz[/tex]

Hope this helps you

HELPPP

Which of the following pairs of elements is most likely to permanently transfer one or more electrons to the
other element?
a. Chlorine and phosphorus
b. Iron and bromine
c. Tin and lead
d. Nitrogen and oxygen

Answers

B is the answer I think hope this helps

can someone please help me? i will give brainliest

Answers

Answer: 3.0 g/cm^3
Explanation: Density = mass/volume

Which of the following describe glands? Check all that apply.

a structure that secretes substances through a duct

a thin layer that separates or connects structures inside the body

a structure that secretes hormones into the bloodstream

a structure usually made from connective and epithelial cells

Answers

Answer:a, c, d

Explanation: just did it on edge

what can i do to change the material like metal clothes line or washing line

Answers

I'm not sure bro but i will try for you

Isotopes have
Question 1 options:

A)

different numbers of both protons and neutrons in their nuclei.

B)

a different number of neutrons in their nuclei.

C)

a different number of protons in their nuclei.

D)

a different number of electrons.
Question 2 (5 points)
An aqueous solution
Question 2 options:

A)

must contain three or more substances.

B)

is a single-phase heterogeneous mixture.

C)

has water as the solvent.

D)

has water as the solute.
Question 3 (5 points)
Which of the following is a homonuclear diatomic molecule?
Question 3 options:

A)

NH3

B)

CO

C)

2CO2

D)

H2
Question 4 (5 points)
Given a container of a solution of 5% HCl, all samples tested from this same bottle will have the same mass ratio of hydrogen to chlorine. This is an application of
Question 4 options:

A)

the law of conservation of energy.

B)

the law of multiple proportions.

C)

the law of conservation of mass.

D)

the law of constant composition.
Question 5 (5 points)
Elements in the same period
Question 5 options:

A)

have the same principal quantum number.

B)

form bonds with the same type of elements.

C)

have the same number of valence electrons.

D)

have the same number of protons.

Answers

Answer:

question 1 answer is b

Explanation:

istopes equal to same atomic number but different mass number

If heat is required for a chemical reaction to occur, from where does the energy come?

Answers

Answer:

Chemical energy is energy stored in the bonds of chemical compounds, like atoms and molecules. This energy is released when a chemical reaction takes place. Usually, once chemical energy has been released from a substance, that substance is transformed into a completely new substance.

Explanation:

How is the term stable used in the text?

Answers

Answer:

When something is stable, it's fixed and steady. If you needed advice, you'd probably go to your most stable friend, the one least likely to act crazy or be easily upset.

Explanation:

Whether you're talking about an object or a person, the adjective stable implies reliability and strength. You can describe a government as stable, or a relationship, or a desk. A completely different meaning of stable is the noun "building used for housing horses or other animals." Both senses of the word come from the Latin stabilis, "firm or steadfast."

illustrate the respiratory system​

Answers

I hope this has the information that you need

A chemist is asked to determine the specific heat capacity of an unknown mineral. The 149-g sample was heated to 92.7°C and placed into a calorimeter containing 81.4 g of water at 20.0°C. The heat capacity of the calorimeter was 12.8 J/K. The final temperature in the calorimeter was 23.7°C. What is the specific heat capacity (in J/g°C) of the mineral? Enter to 4 decimal places.​

Answers

Answer:

The specific heat of the mineral is 0.1272J/g°C

Explanation:

The sample is given energy to the calorimeter and the sample of water.

The energy released for the sample is equal to the energy absorbed for both the calorimeter and the water:

C(Sample)*m*ΔT = C(Calorimeter)*ΔT + C(water)*m*ΔT

Where C is specific heat

m is mass of the sample and water

And ΔT is change in temperature

C(Sample)*149g*(92.7°C-23.7°C) = 12.8J/K*(23.7°C-20.0°C) + 4.184J/g°C*81.4g*(23.7°C-20.0°C)

C(Sample)*10281g°C = 47.36J + 1260.1J

C(Sample) = 0.1272J/g°C

The specific heat of the mineral is 0.1272J/g°C

The specific heat of the mineral is 0.1272J/g°C

Calculation of the specific heat:

The energy released for the sample should be equivalent to the energy absorbed for both the calorimeter and the water:

So,

C(Sample)*m*ΔT = C(Calorimeter)*ΔT + C(water)*m*ΔT

here C is specific heat

m is mass of the sample and water

And ΔT is change in temperature

Now

C(Sample)*149g*(92.7°C-23.7°C) = 12.8J/K*(23.7°C-20.0°C) + 4.184J/g°C*81.4g*(23.7°C-20.0°C)

C(Sample)*10281g°C = 47.36J + 1260.1J

C(Sample) = 0.1272J/g°C

learn more about heat here: https://brainly.com/question/15873257

What are the four main types of tissues in the human body?

Answers

connective tissue, epithelial tissue, muscle tissue, and nervous tissue.

Answer:

epithelial tissue, connective tissue, muscle tissue, and nerve tissue

Explanation:

In which phase transition do molecules move directly from a state involving vibration of particles in a fixed position to a state involving random movement of high-speed particles?
evaporation
sublimation
freezing
deposition

Answers

Sublimation

would be your answer because it releases other cells out and causes the needy of cells to evaporate and sink.

sublimation is the phase transition do molecules move directly from a state involving vibration of particles in a fixed position to a state involving random movement of high-speed particles.

What is Sublimation?

In the process of printing sublimation shirts, an image is first printed on a special sheet of paper before being transferred to a different material, typically polyester or a polyester blend. After that, heat is applied to the ink until it fuses with the fabric.

Sublimation shirt printing is more expensive than other procedures, but it produces shirts that stay longer and don't peel or crack over time.

he primary distinction between sublimation and heat transfer is that during sublimation, just the ink transfers to the substrate. A transfer layer is frequently also transferred to the material during the heat transfer procedure.

Therefore, sublimation is the phase transition do molecules move directly from a state involving vibration of particles in a fixed position to a state involving random movement of high-speed particles.

To learn more about Sublimation, refer to the link:

https://brainly.com/question/29304516

#SPJ7

what is the density of if mass equals 4.98 volume is 5

Answers

Answer:

4.98/5 = 0.996 (don't forget to add your units)

Explanation:

Density= Mass/Volume

If your mass is 4.98_ (units of measurement are missing ) and your volume is 5 (units of measurement are missing) You plug the numbers into the equation:

4.98/5= 0.996 (don't forget to add your units)  

Why do you think the hot red water sank to the bottom?

Answers

Answer:

i did this in school :) but Hot water will rise to the top because it is less dence and cold water will sink to the bottom because it is more dence

Explanation:

The red water is more dense then the water on top so it sinks to the bottom

The smallest possible particle of an element is a(n)
RE
??

Answers

Answer:

An atom is the smallest particle of an element that still has the properties of that element. Atoms, in turn, are composed of subatomic particles, including negative electrons, positive protons, and neutral neutrons. The number of protons in an atom determines the element it represent

Explanation:

Convert 3.4 moles of sodium oxalate into grams. Show all your work .

Answers

Answer:

m = 455,6 g

Explanation:

The mass can be determined by calculating the amount of substance times the molar mass:

m = n * M

To do this, you first have to calculate the molar mass of sodium oxalate. It is made up of the molar masses of the individual atoms. The molecular formula of sodium oxalate is:

[tex]Na_{2}C_{2}O_{4}[/tex]

M(Na) = 23 g/mol; M(C) = 12 g/mol; M(O) = 16 g/mol

M(Na2C2O4) = 2 * M(Na) + 2 * M(C) + 4 * M(O)

M(Na2C2O4) = 2 * 23 g/mol + 2 * 12 g/mol + 4 * 16 g/mol

M(Na2C2O4) = 134 g/mol

m = n * M

m = 3,4 mol * 134 g/mol

m = 455,6 g

is beeswax a mineral, a rock or neither

Answers

Answer:

niether

Explanation:

Beeswax is neither a mineral nor a rock it is supposed to be a heterogenous mixture.

What are minerals?

Minerals are defined as a chemical compound which has a well -defined composition and possesses a specific crystal structure.It occurs naturally in the pure form.

If a compound occurs naturally in different crystal structure then each structure is considered as a different mineral.The chemical composition of a mineral varies depending on the presence of small impurities which are present in small quantities.

Some minerals can have variable proportions of two or more chemical elements which occupy equivalent position in the crystal structure.It may also have variable composition which is split into separate species.

Physical properties of minerals include color,streak, luster,specific gravity and cleavage.

Learn more about minerals,here:

https://brainly.com/question/18078524

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