HChem Unit 4 Test Review

Which of the following is an INCORRECT conversion factor?

• 1 mol = 46.03 g Ca(OH)₂

• 151.92 g FeSO₄ = 1 mol

• 1 mol = 178.49 g Hf

• 6.022 x 10²³ molecules = 1 mol

Calculate the molar mass of Ba(C₂H₃O₂)₂

• 255.3 g/mol

• 237.3 g/mol

• 228.3 g/mol

• 196.3 g/mol

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%

What percentage of the total atomic mass of magnesium bromide (MgBr₂) is composed of magnesium?

• 13%

• 43%

• 63%

• 87%

48.86 g of cobalt is equal to how many moles of cobalt?

• 2879 moles

• 8.291 moles

• .8291 moles

• .829 moles

Tags

NGSS.HS-PS1-7

How many molecules of water are in a 821.3 g sample?

• 45.58 molecules

• 8.232 x 10²⁵ molecules

• 8.909 x 10²⁷ molecules

• 2.744 x 10²⁵ molecules

What is the mass of 4.98 x 10²⁴ atoms of Zn?

• 541 g

• 8.27 g

• .122 g

• 4.59 x 10⁴⁶ g

Tags

NGSS.HS-PS1-7

How many moles of sodium chloride are in a 321.8 g sample?

• 18810 moles

• 3.315 x 10²⁴ moles

• 5.507 moles

• 4.767 moles

Tags

NGSS.HS-PS1-7

How many formula units of calcium chloride are in a 25.69 g sample?

• 1.394 x 10²³ F.U.'s

• 2851 F.U.'s

• .2315 F.U.'s

• 3.845 x 10²⁵ F.U.'s