PERCENT COMPOSITION PRACTICE

What is the percent by mass of chlorine in NaCl?

• 39%
• 61%
• 35%
• 65%

What is the percent composition by mass of sulfur in the compound MgSO₄ (gram formula mass = 120 g/mol)?

• 20%
• 27%
• 46%
• 53%

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)

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

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

Which list of number of atoms in MgF₂ is right?

• Mg : 1--  F :  1
  
• Mg : 1 -- F :  2
  
• Mg :  2 --  F :   1
  
• Mg : 0 --   F :  1
  

Tags

NGSS.MS-PS1-1

Calculate the molar mass of Ba(C₂H₃O₂)₂

• 255.3 g/mol

• 237.3 g/mol

• 228.3 g/mol

• 196.3 g/mol

What is the molar mass of table salt (NaCl)?

• 116.886 g/mol
• 35.453 g/mol
• 22.990 g/mol
• 58.443 g/mol

What is the molar mass of (NH₄)₂CO₃ ?

• 144 g
• 138 g
• 96 g
• 78 g

Tags

NGSS.MS-PS1-1

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

How many grams of carbon dioxide are present in a sample containing 80.0 moles of CO₂?

• 0.550 grams

• 3520 grams

• 44.0 grams

• 1.82 grams