Mass and Percent Composition Test

What is the percent by mass of oxygen in MgO?

• 20%

• 40%

• 50%

• 60%

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 fluorine in CaF₂ (gram-formula mass = 78 g/mol)?

• 24%
• 49%
• 51%
• 65%

What is the molar mass of CO₂?

• 12 g/mol

• 16 g/mol

• 32 g/mol

• 44 g/mol

What are the units of molar mass?

• grams

• moles

• moles/gram

• grams/mole

Find the molar mass of KCl

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

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

• 20%
• 27%
• 46%
• 53%

What is the gram formula mass of Silicon Tetrabromide (SiBr4)?

• 107.99 g/mol

• 347.70 g/mol

• 187.89 g/mol

• 267.80 g/mol

The mass % of aluminum in aluminum sulfate is:

• 12.93%

• 45.70%

• 7.89%

• 35.94%

• 15.77%

Which list of number of atoms in Mg(NO₃)₂ is right?

• Mg : 1--NO :  6
  
• Mg : 1-- N :  6--O:  6
  
• Mg :  1-- N:   1--  O: 5
  
• Mg :  1-- N: 2--  O: 6
  

Tags

NGSS.MS-PS1-1