Unit 5 Review

What is the molar mass NaCl?

• 58 grams
• 22.95 grams
• 162 grams
• 6.02 x 10²³

What is the molar mass of H₂O?

• 6.02 x 10²³
• 16 grams
• 18 grams
• 15.99999 grams

The mole is a...

• Unit to measure the amount of atoms in a substance

• Unit to measure distance

• Unit to measure time of atomic decay

• Unit used to measure the size of each atom in a substance

How many moles are in 32 grams of Oxygen (O)? 

• 3
• 2
• 1
• 4

Tags

NGSS.HS-PS1-7

How many atoms are in 3.5 moles of arsenic atoms?

• 5.8 x 10^-24
• 7.5 x 10¹
• 2.1 x 10²⁴
• 1.7 x 10²³

How many moles there are in 5.68 x 10²⁴ formula units of AlCl₃?

• 3.42 x 10²⁴ moles

• 9.44 x 10²⁴ moles

• 9.44 moles

• 3.42 moles

Tags

NGSS.HS-PS1-7

Find the mass of 5.82 mol of MgCl₂. Round to the nearest tenth.

• 552.9 g

• 436.8 g

• 55.2 g

• 555.9 g

Tags

NGSS.HS-PS1-7

In which compound is the percent composition by mass of Cl equal to 42%?

• HClO (gram formula mass = 52 g/mol)
• HClO₂ (gram formula mass = 68 g/mol)
• HClO₃ (gram formula mass = 84 g/mol)
• HClO₄ (gram formula mass = 100 g/mol)

Which pair has the same empirical formula?

• NaCrO₄ and Na₂Cr₂O₇
• C₂H₄O₂ and C₆H₁₂O₆
• C₃H₆O₃ and C₂H₆O₂
• CH₄ and C₂H₆

You are given the following percentages: 40.05% S and 59.95% O. Find the empirical formula for these elements.

• SO

• SO₂

• SO₃

• SO₄