C9 TEST

How do you determine the amount of product made?

• Add the limiting factor to the product and compare the two.

• Limiting reactant × (mole ratio of REACTANT/ limiting reactant) × molar mass of product

• Limiting reactant / (mole ratio of product / limiting reactant) × molar mass of product

• Limiting reactant × (mole ratio of PRODUCT / limiting reactant) × molar mass of product

What is a limiting reactant?

• The reactant that is used up last and prevents more product from being made.

• The reactant that is used up first and prevents more product from being made.

• The reactant that makes the product.

• 'The substance that is in excess that doesn't get used up as a reactant.

If 2.5 moles of zinc react with 6.0 moles of hydrochloric acid in the equation Zn + 2HCl = ZnCl2 + H2, what is the limiting reactant?

• Zn

• HCl

• ZnH

• ZnCl

Which of the following calculations is NOT needed to determine the empirical formula?

• Percentage composition

• Composition in moles

• Mass composition

• Moles to mass

What is the percent composition of Cu₂S?

• 20% Cu, 80% S

• 50% Cu, 50% S

• 80% Cu, 20% S

• 66% Cu, 34% S

What is the percent composition of H₂SO₃?

• 2.5% H, 39% S, 58.5% O

• 33% H, 16% S, 51% O

• 2.5% H, 58.5% S, 39% O

• 58.5% H, 39% S, 2.5% O

What is a coefficient?

• A whole number that appears as a subscript at the end of a formula in a balanced chemical equation.

• A whole number that appears as a superscript at the end of a formula in a balanced chemical equation.

• A whole number that appears in front of a compound or element in a balanced chemical equation.

• A whole number that appears as a subscript in front of a formula in a balanced chemical equation.

Conservation of matter means that:

• Matter is always created and destroyed.

• Matter always turns into energy.

• Matter is flexible; it can be created, destroyed, or turned into energy.

• Matter is never created nor destroyed.

Choose the correctly balanced equation for the following reaction:

Sodium + water → sodium hydroxide + hydrogen gas

• Na₂O + H₂O → NaOH + H

• Na₂ + H₂O → NaOH + H

• Na + H₂O → NaOH + H₂

• 2Na + 2H₂O → 2NaOH + H₂

What is NOT a step in determining the formula of a hydrate?

• Find the water to anhydrate mole ratio.

• Convert the starting mass of hydrate to moles.

• Use the mole ratio to write the formula.

• Convert the mass of water to moles.