Mole Concept and Molecular Formula Review

The molecular formula for a carbon and hydrogen compound is C₈H₁₈. What is the empirical formula?

• C₈H₁₈

• C₉H₄

• C₁₈H₈

• C₄H₉

What is the percent composition of hydrogen in water?

• 89.8%

• 11.2%

• 66.7%

• 33.3%

What is the molar mass of NaCl?

• 58.45g/mol

• 28g/mol

• 12g/mol

• 6.02 x 10²³

Calculate the % composition by mass of oxygen present in H₂SO₄.

• 16.3%

• 65.25%

• 32.6%

• 57.14%

Tags

NGSS.HS-PS1-7

What is the molecular formula if the empirical formula is CH₂O and the molecular molar mass is 180.18?

• CH₂O
• C₂H₄O₂
• C₄H₈O₄
• C₆H₁₂O₆

Tags

NGSS.MS-PS1-1

What is the molecular formula for a compound with the empirical formula: K₂SO₄ and a molecular mass of 696g.

• K₂SO₄ 
• K₈SO₁₆
• K₈S₄O₈ 
• K₈S₄O₁₆ 

Which of the following represents an empirical formula?

• H₂O₂
• HC₂O₄
• H₂O₆
• H₁₂O₄₈

What is the best definition for molecule? 

• A molecule is formed when two or more atoms join together chemically.
• A molecule is made of only one atom. 

Tags

NGSS.MS-PS1-1

What is the symbol of the element: gold?

• Ag
• As
• Ap
• Au

What is the total number of atoms in this molecule?

• 2
• 4
• 1
• 6

Tags

NGSS.MS-PS1-1