Unit 2: Types of Chemical Reactions and Solution Stoich MC

What mass of Au is produced when 0.0500 mol of Au₂S₃ is reduced completely with excess H₂?

• 9.85 g

• 19.7 g

• 24.5 g

• 39.4 g

• 48.9 g

Tags

NGSS.HS-PS1-7

When the equation above is balanced and all coefficients are reduced to their lowest whole-number terms, the coefficient for O₂(g) is

• 6

• 7

• 12

• 14

• 28

A 1 .O L sample of an aqueous solution contains 0.10 mol of NaCl and 0.10 mol of CaC12. What is the minimum number of moles of AgNO, that must be added to the solution in order to precipitate all of the Cl- as AgCl(s)? (Assume that

AgCl is insoluble.)

• 0.10 mol

• 0.20 mol

• 0.30 mol

• 0.40 mol

• 0.60 mol

When the equation above is balanced and all coefficients reduced the lowest whole-number terms, the coefficient for OH^-(aq) is

• 1

• 2

• 3

• 4

• 6

Tags

NGSS.HS-PS1-7

According to the balanced equation above, how many moles of HI would be necessary to produce 2.5 mol of I₂, starting with 4.0 mol of KMnO₄, and 3.0 mol of H₂SO₄?

• 20.

• 10.

• 8.0

• 5.0

• 2.5

Tags

NGSS.HS-PS1-7

A 40.0 mL sample of 0.25 M KOH is added to 60.0 mL of 0.15 A4 Ba(OH)₂. What is the molar concentration of OH^-(aq) in the resulting solution? (Assume that the volumes are additive.)

• 0.10 M

• 0.19 M

• 0.28 M

• 0.40 M

• 0.55 M

Tags

NGSS.HS-PS1-2

What is the final concentration of barium ions, [Ba²⁺], in solution when 100. mL of 0.10 M BaCl₂(aq) is mixed with 100. mL of 0.050 M H₂SO₄(aq)?

• 0.00 M

• 0.012 M

• 0.025 M

• 0.075 M

• 0.10 M

Tags

NGSS.HS-PS1-5

When 100 mL of 1 .O M Na₃PO₄, is mixed with 100 mL of 1.O M AgNO₃, a yellow precipitate forms and [Ag⁺] becomes negligibly small. Which of the following is a correct listing of the ions remaining in solution in order of increasing concentration?

• [PO₄^3-] < [NO₃^-] < [Na⁺]

• [PO₄^3-] < [Na⁺] < [NO₃^-]

• [NO₃^-] < [PO₄^3-] < [Na⁺]

• [Na⁺] < [NO₃^-] < [PO₄^3-]

• [Na⁺] < [PO₄^3-] < [NO₃^-]

After completing an experiment to determine gravimetrically the percentage of water in a hydrate, a student reported a value of 38 percent. The correct value for the percentage of water in the hydrate is 51 percent. Which of the following is the most likely explanation for this difference?

• Strong initial heating caused some of the hydrate sample to spatter out of the crucible.

• The dehydrated sample absorbed moisture after heating.

• The amount of the hydrate sample used was too small.

• The crucible was not heated to constant mass before use.

• Excess heating caused the dehydrated sample to decompose.

Propane gas, C₃H₈, burns in excess oxygen gas. When the equation for this reaction is correctly balanced and all coefficients are reduced to their lowest whole number terms, the coefficient for O₂ is

• 4

• 5

• 7

• 10

• 22