1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
nekit [7.7K]
3 years ago
9

One way the U.S. Environmental Protection Agency (EPA) tests for chloride contaminants in water is by titrating a sample of silv

er nitrate solution. Any chloride anions in solution will combine with the silver cations to produce bright white silver chloride precipitate. Suppose an EPA chemist tests a sample of groundwater known to be contaminated with iron(III) chloride, which would react with silver nitrate solution like this: (aq) (aq) (s) (aq) The chemist adds M silver nitrate solution to the sample until silver chloride stops forming. She then washes, dries, and weighs the precipitate. She finds she has collected of silver chloride. Calculate the concentration of iron(III) chloride contaminant in the original groundwater sample. Be sure your answer has the correct number of significant digits.
Chemistry
1 answer:
ella [17]3 years ago
7 0

Answer:

3.8x10⁻⁵ M

Explanation:

By the reaction given, the stoichiometry between FeCl3 and AgNO3 and AgCl is 1:3:3. The molar mass of AgCl is 143.32 g/mol, so the number of moles that was formed is:

n = mass/molar mass

n = 0.0036g/143.32g/mol

n = 2.51x10⁻⁵ mol

Thus, the number of moles of FeCl3 that had precipitated was:

1 mol of FeCl3 ------------ 3 moles of AgCl

x -------------2.51x10⁻⁵ mol

By a simple direct three rule:

x = 8.37x10⁻⁶ mol

The precipitation is a reversible reaction, and, for the AgCl, is has an equilibrium constant Kps = 1.8x10⁻¹⁰, then, the solubility, S, (the maximum concentration of the ions that will not precipitate) can be calculated:

S² = Kps

S = √1.8x10⁻¹⁰

S = 1.34x10⁻⁵ mol/L

The volume of the sample was 250 mL = 0.250 L, so the number of moles of Cl⁻ that was not precipitated is:

n = 1.34x10⁻⁵ mol/L*0.250 L

n = 3.35x10⁻⁶ mol

Because of the stoichiometry:

1 mol of FeCl3 ------ 3 moles of Cl-

y ------ 3.35x10⁻⁶ mol

By a simple direct three rule:

y = 1.12x10⁻⁶ mol of FeCl3

The total number of moles of FeCl3 is then:

n = x + y

n = 9.5x10⁻⁵ mol

The concentration is the number of moles dived by the volume:

9.5x10⁻⁵ /0.250 = 3.8x10⁻⁵ M

You might be interested in
Approximately _____ elements occur naturally on earth.
boyakko [2]
90 elements occur naturally on earth.
5 0
3 years ago
Read 2 more answers
The radioactive isotope used in the dating of fossils thought to be less than 40,000 years old is ________________.
Fantom [35]

Answer:

The answer is Radiocarbon

8 0
2 years ago
Which of the following statements most likely
cupoosta [38]

Answer:

Forming a problem requires the scientist to  use creativity to imagine new solutions.

Explanation:

Albert Einstein remains a critically prominent figure who conducted remarkable, ground-breaking research that not only formed the foundations of modern physics but also strongly affected the scientific world. It is difficult to teach imagination but it can be harnessed and accepted. Nothing incites our imaginative impulses we love more than the prospect of immediate creative inspiration. And creativity hits its full potential when paired with the experience, insights, and skills people gained by questioning the real-life problems.

6 0
3 years ago
Read 2 more answers
Which statement defines specific heat capacity for a given sample
avanturin [10]

The statement that defines the specific heat capacity for a given sample is the quantity of heat that is required to raise 1 g of the sample by 1°C (Kelvin) at a constant pressure.

<h3>What is specific heat capacity?</h3>

Specific heat capacity is the of heat to increase the temperature per unit mass.

The formula to calculate the specific heat is Q = mct.

The options are attached here:

  1. The temperature of a given sample is 1 %.
  2. The temperature that a given sample can withstand.
  3. The quantity of heat that is required to raise the sample's temperature by 1 °C1 °C (Kelvin).
  4. The quantity of heat that is required to raise 1 g of the sample by 1°C (Kelvin) at a constant pressure.

Thus, the correct option is 4. The quantity of heat that is required to raise 1 g of the sample by 1°C (Kelvin) at a constant pressure.

Learn more about specific heat capacity

brainly.com/question/1747943

#SPJ1

8 0
2 years ago
How long does it take for a 12.62g sample of ammonia to heat from 209K to 367K if heated at a constant rate of 6.0kj/min? The me
Georgia [21]
First, consider the steps to heat the sample from 209 K to 367K.

1) Heating in liquid state from 209 K to 239.82 K

2) Vaporaizing at 239.82 K

3) Heating in gaseous state from 239.82 K to 367 K.


Second, calculate the amount of heat required for each step.

1) Liquid heating

Ammonia = NH3 => molar mass = 14.0 g/mol + 3*1g/mol = 17g/mol

=> number of moles = 12.62 g / 17 g/mol = 0.742 mol

Heat1 = #moles * heat capacity * ΔT

Heat1 = 0.742 mol * 80.8 J/mol*K * (239.82K - 209K) = 1,847.77 J

2) Vaporization

Heat2 = # moles * H vap

Heat2 = 0.742 mol * 23.33 kJ/mol = 17.31 kJ = 17310 J

3) Vapor heating

Heat3 = #moles * heat capacity * ΔT

Heat3 = 0.742 mol * 35.06 J / (mol*K) * (367K - 239.82K) = 3,308.53 J

Third, add up the heats for every steps:

Total heat = 1,847.77 J + 17,310 J + 3,308.53 J = 22,466.3 J

Fourth, divide the total heat by the heat rate:

Time = 22,466.3 J / (6000.0 J/min) = 3.7 min

Answer: 3.7 min


3 0
3 years ago
Other questions:
  • Your mom is playing the drums in the basement. Whenever she hits the drum with all her force, the box next to the drums shakes,
    11·1 answer
  • What is water in a scientific knowledge​
    11·1 answer
  • Which element is a liquid at 758 K and standard pressure?
    9·1 answer
  • For the reaction 8 H 2 S ( g ) − ⇀ ↽ − 8 H 2 ( g ) + S8 ( g ) 8H2S(g)↽−−⇀8H2(g)+S8(g) the equilibrium concentrations were found
    9·1 answer
  • Write an equation for the reaction of solid aluminum metal with hydrochloric acid (hydrogen monochloride) dissolved in water to
    5·1 answer
  • Explain why hydrogen gas is given off when a reactive metal undergoes a single-displacement reaction with water.
    10·1 answer
  • BRAINLIEST IF ANSWERED CORRECTLY WITH EXPLANATION! HELP PLEASE:)
    15·1 answer
  • Is #11 balanced or unbalanced?
    11·2 answers
  • Which is a nonpoint source of pollution?
    15·2 answers
  • The burning of ethane produces both co2 and H2O. if 400 ml of CO2 is produced at 30°C and 740 torr, what volume of water vapor w
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!