percent composition

What is the percent by mass of oxygen in MgO?

• 20%
• 40%
• 50%
• 60%

What is the percent by mass of magnesium in MgO?

• 20%
• 40%
• 50%
• 60%

What is the percent by mass of fluorine in CaF₂ (gram-formula mass = 78 g/mol)?

• 24%
• 49%
• 51%
• 65%

What is the percent by mass of calcium in CaF₂ (gram-formula mass = 78 g/mol)?

• 24%
• 49%
• 51%
• 65%

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

• 20%
• 27%
• 46%
• 53%

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

• 20%
• 27%
• 46%
• 53%

Tags

NGSS.HS-PS1-7

Carbon monoxide, a deadly gas, has a chemical formula of CO (one carbon atom with one oxygen atom). If you look at the total atomic mass of CO, does carbon or oxygen make up more of the mass?

• carbon

• oxygen

• they are exactly the same

• it is impossible to tell

Tags

NGSS.MS-PS1-1

What percentage of the total atomic mass of carbon monoxide (CO) is composed of carbon?

• 29%

• 43%

• 57%

• 73%

Tags

NGSS.HS-PS1-7

Magnesium bromide (one magnesium atom with two bromine atoms) has a chemical formula of MgBr₂. If you look at the total atomic mass of MgBr₂, does magnesium or bromine make up more of the mass?

• bromine

• magnesium

• they are exactly the same

• it is impossible to tell

Tags

NGSS.MS-PS1-1