AP Chem Unit 4

Front

Dissolving salt in water is always a chemical change.

Back

False: Dissolving salt in water is a physical change because the salt can be recovered by evaporation.

Front

What is a strong electrolyte?

Back

A strong electrolyte is a substance that dissociates completely into ions in solution.

Front

Given the reaction CH4 + O2 -> CO2 + H2O, if you have 4g of CH4 and 4g of O2, identify the limiting reactant and the products formed.

Back

Limiting reactant: O2; Products: 2g CO2 and 2.25g H2O.

Front

If 4 moles of NH3 react with O2 to produce N2 and H2O, how many moles of H2O will form?

Back

6 moles of H2O will form.

Front

Which of the following represents a species that is reduced? Ca(s) → Ca2+, Hg(l) → Hg2+, Fe2+ (aq) → Fe3+ (aq), NO3- (aq) → NO (g)

Back

NO3- (aq) → NO (g) is the reduction reaction.

Front

What is a limiting reactant?

Back

The limiting reactant is the substance that is completely consumed in a chemical reaction, limiting the amount of product formed.

Front

Define oxidation in terms of electron transfer.

Back

Oxidation is the process of losing electrons during a chemical reaction.

Front

Define reduction in terms of electron transfer.

Back

Reduction is the process of gaining electrons during a chemical reaction.

Front

What is the general rule for balancing chemical equations?

Back

The number of atoms of each element must be the same on both sides of the equation.

Front

What is the molar mass of CH4 (methane)?

Back

The molar mass of CH4 is approximately 16.04 g/mol.