Conservation of Mass

Which of the following is true about a balanced chemical equation?

• Reactants are on the right

• Products are on the left

• Subscripts can be changed

• Coefficients can be changed

If the mass of one product was 3 grams, and the mass of another product was 4 grams, what was the mass of the reactants?

• 1 gram

• 4 grams

• 7 grams

• 12 grams

2 AgI + Na2S → Ag2S + 2 NaI

What is the mole ratio?

• 2:1:1:2

• 1:2:1:2

• 2:2:1:2

• 2:1:1:1

Ba3N2 + 6 H2O → 3 Ba(OH)2 + 2 NH3

What is the mole ratio?

• 3:2:6:2

• 1:6:3:2

• 3:6:3:2

• 1:2:3:6

If the mass of one reactant was 10 grams, and the mass of another reactant was 2 grams, what was the mass of the products?

• 2 grams

• 8 grams

• 20 grams

• 12 grams

Every substance has a different molar mass.

• True

• False

Heavier elements have a larger amount of atoms per mole than lighter elements.

• True

• False

1 mole is 6.02 x 23¹⁰ atoms.

• True

• False

10 KClO3 + 3 P4 → 3 P4O10 + 10 KCl

In this equation, what are the reactants?

• KClO3 and P4O10

• KClO3 and P4

• P4O10 and P4

• P4O10 and KCl

10 KClO3 + 3 P4 → 3 P4O10 + 10 KCl

In this equation, what are the products?

• KClO3 and P4O10

• KClO3 and P4

• P4O10 and P4

• P4O10 and KCl