Unit 8 Review

A chemist combines 1.00L of 2.00M AgNO₃(aq) with 1.00L of

4.00M NaCl(aq) in an Erlenmeyer flask. Both the AgNO₃(aq) solution and the NaCl(aq) solution are colorless.

After the mixture has been stirred, a cloudy white substance is observed at the bottom of the flask.

Which of the following is the complete ionic equation for the reaction that occurs in the beaker?

• Ag+(aq) + Cl−(aq) → AgCl(s)

• Na+(aq) + NO₃−(aq) → NaNO₃(s)

• Ag+(aq) + NO₃−(aq) + Na+(aq) + Cl−(aq) → AgCl(s) + Na+(aq) + NO₃−(aq)

• NaCl(aq) + AgNO₃(aq) → AgCl(s) + NaNO₃(aq)

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Tags

NGSS.HS-PS1-7

NGSS.HS-PS1-2

Balance the chemical equation below using coefficients. The stoichiometric coefficient for oxygen gas is... __ NH₃(l) + __ O₂(g) → __ NO₂(g) + __ H₂O(l)

• 3

• 4

• 6

• 7

Mg(s) + 2 HCl(aq) → MgCl2(aq) + H2(g)

Molar Masses (g/mol): Mg = 24.3g/ mol, HCl = 36.5 g/mol, MgCl₂ = 95.2g/mol, H₂ = 2.0g/mol

What mass of solid magnesium is needed to completely react with 1 mole of dissolved HCl?

• 12.2 g

• 18.3 g

• 24.3 g

• 48.6 g

When 10.0 grams of magnesium react with excess hydrochloric acid, investigators expected to collect 39.2 g of magnesium chloride. Instead, the investigators only collected 30.0 g of magnesium chloride. What was the percent yield of this experiment?

• 25.5%

• 33.0%

• 76.5%

• 131%

Tags

NGSS.HS-PS1-7

Mg(s) + 2 HCl(aq) → MgCl2(aq) + H2(g)

Molar Masses (g/mol): Mg = 24.3g/ mol, HCl = 36.5 g/mol, MgCl₂ = 95.2g/mol, H₂ = 2.0g/mol

If the reaction produces 0.400 L of 1.5 M MgCl2, which setup shown will correctly calculate how many grams of HCl reacted with excess solid magnesium?

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Tags

NGSS.HS-PS1-7

In the equation 2KClO₃ → 2KCl + 3 O₂, how many moles of oxygen are produced when 3.0 moles of KClO₃ decomposes completely?

• 1 mol O₂

• 1.5 mol O₂

• 3.0 mol O₂

• 4.5 mol O₂

Tags

NGSS.HS-PS1-7

When the limiting reactant in a chemical reaction is completely used up...

• the reaction slows down.

• the reaction stops.

• the excess reactants begin combining.

• the reaction speeds up.

In the chemical reaction 4A + 3B → 5C + 9D, the substances involved have been substituted by letters. If 14 moles of A react with 15 moles of B, what is the limiting reactant?

• Substance A

• Substance B

• Substance C

• Substance D

A solution of (NH₄)₂SO₄ is combined with a solution of Ba(NO₃)₂, as shown in the diagram above. (Gray circles = NH₄, Striped = SO4, Black = Ba, White = NO₃) Which of the following particle diagrams represents the formation of the correct precipitate?

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Tags

NGSS.HS-PS1-2