ch 7

How many hydrogen atoms are in the compound: (NH₄)₂CO₃

• 3
• 4
• 6
• 8

What is the formula mass of CO₂?

• 44 grams
• 44 amu
• 0.44 grams
• 2.6 x 10²⁵ atoms

What is the percent composition of nitrogen in NH₃?

• 25%
• 14%
• 28%
• 82%

Which of the following is an empirical formula?

• C₃H₃
• Li₂CO₃
• Na₂O₂
• C₆H₁₂O₆

How many moles are contained in 45 grams of aluminum?

• 27 mol
• 1215 mol
• 1.7 mol
• 57 mol

How many atoms of are contained in a mole of sodium?

• 6.02 x 10²³ atoms
• 11 atoms
• 23 atoms
• 2 atoms

What is the purpose of using moles in chemistry?

• To count the number of atoms or molecules

• To measure the temperature of a substance

• To determine the color of a compound

• To calculate the volume of a solution

How many moles are in 6 grams of carbon dioxide (CO₂)?

• 0.25 mol

• 0.50 mol

• 1.00 mol

• 2.00 mol

1 mol = 6.02 x 10²³ _______

• particles

• grams

• liters

• Kelvin

What is the empirical formula of the following molecular formula:  C₃H₆

• C₃H₆
• CH₂
• C₂H₄
• CH₃