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
Snowcat [4.5K]
3 years ago
12

You have two 500.0 ml aqueous solutions. solution a is a solution of a metal nitrate that is 8.246% nitrogen by mass the ionic c

ompound in solution b consists of potassium, chromium, and oxygen; chromium has an oxidation state of +6 and there are two potassiums and 1 chromium in the formula. the masses of the solutes in each solution are the same. when the solutions are added together, a blood-red precipitate forms. after the reaction has gone to completion, you dry the solid and find that it has a mass of 331.8 g. identify the ionic compounds in solution a and solution
b. identify the blood-red precipitate. calculate the concentration (molarity) of all ions in the original solutions. calculate the concentration (molarity) of all ions in the final solution.
Chemistry
1 answer:
almond37 [142]3 years ago
4 0

1) Answer is: the ionic compound in the solution b is K₂CrO₄ (potassium chromate).

Ionic compound in solution b has two potassiums (oxidation number +1), one chromium (oxidation number +6) and four oxygens. Oxidation number of oxygen is -2 and compound has neutral charge:

2 · (+1) + 6 + x · (-2) = 0.

x = 4; number of oxygen atoms.

2) Answer is: the ionic compound in solution a is AgNO₃ (silver nitrate).

ω(N) = 8.246% ÷ 100%.

ω(N) = 0.08246; mass percentage of nitrogen.

M(MNO₃) = M(N) ÷ ω(N).

M(MNO₃) = 14 g/mol ÷ 0.08246.

M(MNO₃) = 169.8 g/mol; molar mass of metal nitrate.

M(M) = M(MNO₃) - M(N) - 3 · M(O).

M(M) = 169.8 g/mol - 14 g/mol - 3 · 16 g/mol.

M(M) = 107.8 g/mol; atomic mass of metal, this metal is silver (Ag).

3) Balanced chemical reaction:  

2AgNO₃(aq) + K₂CrO₄(aq) → Ag₂CrO₄(s) + 2KNO₃(aq).

Ionic reaction:  

2Ag⁺(aq) + 2NO₃(aq) + 2K⁺(aq) + CrO₄²⁻(aq) → Ag₂CrO₄(s) + 2K⁺(aq) + 2NO₃⁻(aq).

Net ionic reaction: 2Ag⁺(aq) + CrO₄²⁻(aq) → Ag₂CrO₄(s).

Answer is: the blood-red precipitate is silver chromate (Ag₂CrO₄).

4) m(Ag₂CrO₄) = 331.8 g; mass of solid silver chromate.

n(Ag₂CrO₄) = m(Ag₂CrO₄) ÷ M(Ag₂CrO₄).

n(Ag₂CrO₄) = 331.8 g ÷ 331.8 g/mol.

n(Ag₂CrO₄) = 1 mol; amount of silver chromate.

From balanced chemical reaction: n(Ag₂CrO₄) : n(AgNO₃) = 1 : 2.

n(AgNO₃) = 2 · 1 mol.

n(AgNO₃) = 2 mol.

m(AgNO₃) = n(AgNO₃) · M(AgNO₃).

m(AgNO₃) = 2 mol · 169.8 g/mol.

m(AgNO₃) = 339.6 g; mass of silver nitrate.

m(AgNO₃) = m(K₂CrO₄).

m(K₂CrO₄) = 339.6 g; mass of potassium chromate.

n(K₂CrO₄) = m(K₂CrO₄) ÷ M(K₂CrO₄).

n(K₂CrO₄) = 339.6 g ÷ 194.2 g/mol.

n(K₂CrO₄) = 1.75 mol; amount of potassium chromate.

5) Chemical reaction of dissociation of silver nitrate in water:

AgNO₃(aq) → Ag⁺(aq) + NO₃⁻(aq).

V(solution a) = 500 mL ÷ 1000 mL/L.

V(solution a) = 0.5 L; volume of solution a.

c(AgNO₃) = n(AgNO₃) ÷ V(solution a).

c(AgNO₃) = 2 mol ÷ 0.5 L.

c(AgNO₃) = 4 mol/L = 4 M.

From dissociation of silver nitrate: c(AgNO₃) = c(Ag⁺) = c(NO₃⁻).

c(Ag⁺) = 4 M; the concentration of silver ions in the original solution a.

c(NO₃⁻) = 4 M; the concentration of silver ions in the original solution a.

6) Chemical reaction of dissociation of potssium chromate in water:

K₂CrO₄(aq) → 2K⁺(aq) + CrO₄²⁻(aq).

V(solution b) = 500 mL ÷ 1000 mL/L.

V(solution b) = 0.5 L; volume of solution b.

c(K₂CrO₄) = n(K₂CrO₄) ÷ V(solution b).

c(AgNO₃) = 1.75 mol ÷ 0.5 L.

c(AgNO₃) = 3.5 mol/L = 3.5 M.

From dissociation of silver nitrate: c(K₂CrO₄) = c/2(K⁺) = c(CrO₄²⁻).

c(K⁺) = 7 M; the concentration of potassium ions in the original solution b.

c(CrO₄²⁻) = 3.5 M; the concentration of silver ions in the original solution b.

7) V(final solution) = V(solution a) + V(solution b).

V(final solution) = 500.0 mL + 500.0 mL.

V(final solution) = 1000 mL ÷ 1000 mL/L.

V(final solution) = 1 L.

n(NO₃⁻) = 2 mol.

c(NO₃⁻) = n(NO₃⁻) ÷ V(final solution)

c(NO₃⁻) = 2 mol ÷ 1 L.

c(NO₃⁻) = 2 M; the concentration of nitrate anions in final solution.

8) in the solution b there were 3.5 mol of potassium cations, but one part of them reacts with 2 moles of nitrate anions:

K⁺(aq) + NO₃⁻(aq) → KNO₃(aq).

From chemical reaction: n(K⁺) : n(NO₃⁻) = 1 : 1.

Δn(K⁺) = 3.5 mol - 2 mol.

Δn(K⁺) = 1.5 mol; amount of potassium anions left in final solution.

c(K⁺) = Δn(K⁺) ÷ V(final solution).

c(K⁺) = 1.5 mol ÷ 1 L.

c(K⁺) = 1.5 M; the concentration of potassium cations in final solution.

You might be interested in
PLS PLS PLS PLS PLS HELP MEEEEEEEE PLS PLS PLS PLS PLS
svetoff [14.1K]
The answer is C: How long does it take distilled water to evaporate from a 5” diameter container?
5 0
3 years ago
Read 2 more answers
Green light has a frequency of about 6.00×1014s−1 . What is the energy of a photon of green light?
murzikaleks [220]
3.25 C because I said so and energy is green
8 0
2 years ago
Calculate the value of the equilibrium constant, Kc, for the reaction below, if 0.208 moles of sulfur dioxide gas, 0.208 moles o
Harman [31]
First, we convert the moles of each substance into the concentration using the volume of the reactor.
[SO₃] = 0.425/1.5 = 0.283 M
[SO₂] = 0.208 / 1.5 = 0.139 M
[O₂] = 0.208/1.5 = 0.139 M
The equilibrium constant is calculated by:
Kc = [SO₃]² / [O₂][SO₂]²
Kc = (0.283)²/(0.139)(0.139)²
Kc = 29.8 = 2.98 x 10¹

The answer is C
8 0
3 years ago
A chemist forms 16.6 g of potassium iodide by combining 3.9 g of potassium with 12.7 g of iodine. Show that these results are co
bezimeni [28]
3.9 g + 12.7 g = 16.6 g

The sum of the masses of potassium and iodine equals the mass of the product, potassium iodide. The results are consistent with he law of conservation of mass.


Hope this heeeelllllllpppppppp
3 0
3 years ago
What does RNA do?
MariettaO [177]

Answer:

b, its a polymer that translates genetic information.

7 0
3 years ago
Read 2 more answers
Other questions:
  • Why does the structure of the plasma membrane make this type of transport necessary for fluids
    9·1 answer
  • Why might the increase of noise in natural areas be a problem, according to scientists studying wildlife? Support your answer wi
    14·1 answer
  • The results of Rutherford’s gold foil experiment disproved the model of the atom that his mentor and colleague had proposed. How
    7·1 answer
  • As the mass of a sample increases, the number of moles present in the sample (increases)
    6·2 answers
  • Which is a heterogeneous mixture?
    9·1 answer
  • (Select all that apply)
    5·2 answers
  • Why is powdered magnesium used in fireworks,<br>rather than magnesium ribbon?​
    10·2 answers
  • Why do we slant the graduated cylinder before dropping the metal cylinder into it?
    14·1 answer
  • Which substance is correctly identified as a homogeneous or heterogeneous mixture?
    5·1 answer
  • What is the boiling point of water at standard atmospheric pressure?
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!