% Composition and Empirical-Molecular Formula

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

• 29%

• 43%

• 57%

• 73%

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

Lithium phosphide (three lithium atoms with one phosphorus atom) has a chemical formula of Li₃P. If you look at the total atomic mass of Li₃P, does lithium or phosphorus make up more of the mass?

• lithium

• phosphorus

• they are exactly the same

• it is impossible to tell

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

Find the percent composition of Cu₂S?

• %Cu= 67.987 %S= 32.013
• %Cu= 79.854   %S= 20.145
• %Cu= 35.946   %S= 64.054

A compound consists of 72.2% magnesium(Mg) and 27.8% nitrogen(N) by mass. What is the empirical formula?

• Mg₄N₃
• MgN₂
• Mg₃N₂ 
• MgN

You are given the following percentages: 40.05% S and 59.95% O. Find the empirical formula for these elements.

• SO
• SO2
• SO3
• SO4

A compound consists of 72.2% magnesium(Mg) and 27.8% nitrogen(N) by mass. What is the empirical formula?

• Mg₄N₃
• MgN₂
• Mg₃N₂ 
• MgN

A formula with the lowest whole # ratio of elements in a compound is called

• Molecular Formula
• Chemical Formula
• Empirical Formula 
• Distance Formula

A chemical formula that shows the actual # and kinds of atoms present in one molecule of a compound is called_________

• ionic formula
• covalent formula
• empirical formula
• molecular formula