Lesson 26 Independent Practice: Law of Conservation of Mass

Zn (65.4g) + 2HCl (72.9g) → ZnCl₂ (?g) + H₂ ( 2.0g)

How much zinc chloride was produced in the equation above?

• 9.7 g

• 136.3 g

• 74.9 g

• 138.6 g

Tags

NGSS.HS-PS1-7

2K + Br₂ → 2KBr

39.1grams of potassium reacts with Bromine. Assuming all of the reactants are used up, how much bromine was used if 119.0 grams of potassium bromide was produced?

• 104 g

• 3.04 g

• 79.9 g

• 158.1 g

Tags

NGSS.HS-PS1-7

O₂ + 2H₂ → 2H₂O

Which of the following statements accurately describes the reaction shown above?

• The mass of the oxygen and hydrogen gases are less than the mass of water.

• The mass of the oxygen and hydrogen gases are greater than the mass of water.

• The mass of the oxygen and hydrogen gases are double the mass of water.

• The mass of the oxygen and hydrogen gases are equal to the mass of water.

Tags

NGSS.HS-PS1-7

C + O₂ → CO₂ + unreacted C

When 40.0 g of carbon reacts with 32.0 g oxygen gas to form carbon dioxide, these is some carbon left over at the end of the reaction. If only 44.0 g of carbon dioxide is produced, how much carbon is left over?

• 126.0 g

• 8.0 g

• 28.0 g

• 4.0 g

Tags

NGSS.HS-PS1-7

2HgO (60.0 g) → O₂ (4.2 g) + 2Hg (?g)

According to the law of conservation of mass, how much mercury was present in the mercury (II) oxide?

• 60.0 g

• 64.2 g

• 55.8 g

• 126.0 g

Tags

NGSS.HS-PS1-7

Is this reaction balanced?

4Fe +3O₂ → 2Fe₂O₃

Use accounting method on paper backup which will be turned in for completion of assignment.

• yes

• no

Tags

NGSS.HS-PS1-7

Is this reaction balanced?

NaOH + HNO₃ → NaNO₃ + H₂O

Use accounting method on paper backup which will be turned in for completion of assignment.

• yes

• no

Tags

NGSS.HS-PS1-7

Is this reaction balanced?

I₂ + Na → 2NaI

Use accounting method on paper backup which will be turned in for completion of assignment.

• yes

• No

Tags

NGSS.HS-PS1-7

Is this reaction balanced?

2Zn + O₂ → 2ZnO

Use accounting method on paper backup which will be turned in for completion of assignment.

• yes

• no

Tags

NGSS.MS-PS1-5

Which set of coefficients will balance this reaction?

CO₂ + H₂O → C₆H₁₂O₆ + O₂

_{(show work on separate paper for each set of coefficients which will be turned in for completion of grade)}

• 6,6,2,6

• 6,12,6,2

• 6,6,1,6

• 6,2,1,4

Tags

NGSS.HS-LS2-5

NGSS.HS-PS1-2

NGSS.HS-PS1-4