U7 Obj. 2 Percent Composition Review

What is the percent by mass of sodium in NaCl?

• 39%
• 61%
• 35%
• 65%

Tags

NGSS.HS-PS1-7

What is the percent by mass of oxygen in MgO?

• 20%
• 40%
• 50%
• 60%

What is the percent composition of Benzene, C₆H₆?

• C = 50%
  H = 50%
• C = 85.7 %
  H = 14.3%
• C = 92.2%
  H = 7.8%
• C = 71.9%
  H = 28.1%

Tags

NGSS.HS-PS1-1

What is the molar mass of PbSO₄

• 303.3 g/mol
• 294.7g/mol
• 163.8g/mol
• 372g/mol

What is the molar mass of CO₂?

• 12 g/mol

• 16 g/mol

• 32 g/mol

• 44 g/mol

Find the percentage composition of Mg in Mg₃(PO₄)₂.

• 27.48% Mg

• 43.11% Mg

• 16.00% Mg

• 12.63% Mg

Calculate the molar mass of Ba(C₂H₃O₂)₂

• 255.3 g/mol

• 237.3 g/mol

• 228.3 g/mol

• 196.3 g/mol

Find the percentage composition of  Mg in Mg₃(PO₄)₂.
   

• 27.48% Mg
• 43.11% Mg
• 16.00% Mg
• 12.63% Mg

Find the molar mass of KCl

• 36 g/mol
• 78 g/mol
• 74 g/mol
• 178 g/mol

What is the molar mass of fluorine gas, F₂?

• 18.998 g/mol
• 38 g/mol
• 9 g/mol
• 18 g/mol