Chapter 5 Exam Review

Which of the following equations are balanced? (You need not balance the equations. Just determine whether they are balanced as written.)

I. Mg + 2 H₂O → Mg(OH)₂ + H₂

II. 4 LiH + AlCl₃ → 2 LiAlH₄ + 2 LiCl

III. 2 KOH + CO₂ → K₂CO₃ + H₂O

IV. 2 Sn + 2 H₂SO₄ → 2 SnSO₄ + SO₂ + 2 H₂O

• II and IV

• I and II

• II and III

• I and III

Tags

NGSS.HS-PS1-7

Consider the equation for the reaction of phosphine with oxygen gas to form tetraphosphorus decoxide and water:

PH₃ + O₂ → P₄O₁₀ + H₂O (not balanced)

 

When the equation is balanced, how many molecules of water are produced for each molecule of P₄O₁₀ formed?

• 4

• 12

• 1

• 6

Tags

NGSS.HS-PS1-7

Refer to the following equation for the reaction of magnesium hydroxide [Mg(OH)₂] with phosphoric acid (H₃PO₄).

 

Mg(OH)₂ + H₃PO₄ →H₂O + Mg₃(PO₄)₂ (not balanced)

 

When the equation is balanced, how many H₃PO₄ molecules must react to produce one Mg₃(PO₄)₂ formula unit? (Just as a molecule is the smallest unit of a molecular compound, a formula unit is the smallest unit of an ionic compound.)

• 3

• 1

• 6

• 2

Tags

NGSS.HS-PS1-7

Refer to the following equation for the reaction of magnesium hydroxide [Mg(OH)₂] with phosphoric acid (H₃PO₄).

 

Mg(OH)₂ + H₃PO₄ →H₂O + Mg₃(PO₄)₂ (not balanced)

 

When the equation is balanced, how many H₂O molecules will be produced for each H₃PO₄ molecule that reacts?

• 3

• 6

• 2

• 1

Tags

NGSS.HS-PS1-7

Refer to the following equation for the reaction of magnesium hydroxide [Mg(OH)₂] with phosphoric acid (H₃PO₄).

 

Mg(OH)₂ + H₃PO₄ →H₂O + Mg₃(PO₄)₂ (not balanced)

 

When the equation is balanced, how many Mg(OH)₂ formula units are needed to react with six H₃PO₄ molecules?

• 6

• 1.5

• 9

• 1

Tags

NGSS.HS-PS1-7

In the reaction 2 H₂(g) + O₂(g) → 2 H₂O(g), with all substances at the same temperature and pressure, the ratio of volumes, for H₂, O₂, and H₂O, respectively, is

• 1:0:1

• 2:1:2

• 1:1:1

• 2:0:2

How many CO₂ molecules are produced in the following reaction if 75 O₂ molecules react?

2 C₈H₁₈(l) + 25 O₂(g) → 16 CO₂(g) + 18 H₂O(l)

• 48 molecules

• 32 molecules

• 100 molecules

• 50 molecules

In the reaction N₂(g) + 3 H₂(g) → 2 NH₃(g), with all substances at the same temperature and pressure, what volume of ammonia is produced when 4.50 L of nitrogen reacts with excess hydrogen?

• 4.50 L

• 6.75 L

• 3.00 L

• 9.00 L

How many oxygen-16 atoms are there in exactly 16 g of oxygen-16?

• 1

• 16

• 256

• 6.02 × 10²³

The mass of 1 mol of carbon-12 atoms is

• 12.011 amu

• 12 g

• 12.011 g

• 12 amu