Question 1What is the mass of a sample of NH3

containing 6.3 × 1024
molecules of NH3?



Question 1

What is the mass of a sample of NH3 containing 6.3 × 1024 molecules of NH3?

A. 157


B. 178 grams

C. 182 grams

D 198 grams

Question 2

Which of the following properties is shared by gases and plasma?

A. They have a definite shape.

B. Their particles are far apart.

C. They consist of uncharged particles.

D. Their particles vibrate in fixed positions.

Question 3

Which of the following steps correctly converts 3 moles of fluorine to an equivalent number of particles of fluorine?

A. Divide Avogadro’s number by 3.

B. Muiply 3 by Avogadro’s number.

C. Divide the atomic mass of fluorine by 3.

D. Muiply 3 by the atomic mass of fluorine.

Question 4

Which term is used to describe the reactant that is used up completely and controls the amount of product that can be produced during a chemical reaction?

A. Catalytic reactant

B. Excess reactant

C. Limiting reactant

D. Theoretical reactant

Question 5

What happens to the average kinetic energy of a gas when the particles of the gas collide against each other at a constant temperature and volume? Explain your answer.

Question 6

During a laboratory experiment, a 3.24-gram sample of NaHCO3 was thermally decomposed. In this experiment, carbon dioxide and water vapors escape and are combined to form carbonic acid. After decomposition, the sample weighed 2.19 grams. Calculate the percentage yield of carbonic acid for the reaction. Describe the calculation process in detail.

NaHCO3 → Na2CO3 + H2CO3