Moles!!

Molar Mass

100

The molar mass of Boron. (Rounded to the nearest hundredth)

What is . . .

10.81 g

200

The molar mass of CO₂

What is . . . 

44.01 g 

300

The molar mass of Aluminum oxide: Al₂O₃

What is . . .

101.96 g

400

The molar mass of Mg(NO₃)₂

What is . . .

148.33 g

500

The molar mass of calcium hydroxide.

What is . . . 

74.1 g

for Ca(OH)₂

One step conversions

100

The number of particles in one mole.

What is . . .

6.02 x 10²³ particles

200

The mass of 2 moles of beryllium (Be)

What is . . .

18.02 g

300

The number of moles in 101.02 g of Sulfur

What is . . .

about 3.15 moles

400

The number of moles in 

2.35 x 10²⁴ atoms of sodium

What is . . .

3.9 moles

500

The mass of 7.8 moles of H₂O₂

What is . . .

265.356 g

(Ok if rounded sooner.)

Two step conversions

100

To change from the mass of a substance to the number of particles you should do these two general steps.

What is . . .

1 divide by the molar mass

2. multiply by 6.02 x 10²³

200

The number of atoms in 24.02 g of Carbon.

What is . . .

1.2 x 10²⁴ atoms

300

The mass of 

2.2 x 10²⁴ atoms of iron (Fe).

What is . . .

204 g

400

The mass of 

3.6 x 10²³ particles of H₂O.

What is . . .

10.77 g

500

The mass of 8.7 x 10²² particles of Al₂O₃

What is . . .

14.74 g

EmpiricalFormulas

100

True or false: The empirical formula shows the lowest ratio of the elements in a compound.

What is . . . 

True

200

Of the following, this formula would represent an empirical formula:

C₃H₆O₃

C₆H₁₂O₆

CH₂O

CH₂O

300

When calculating the empirical formula, a student determines that the substance has a ratio of 

2.02 moles Chlorine, 

2.02 moles Carbon, and 

4.04 moles hydrogen.  

This would be how they would write the empirical formula.

What is . . .

ClCH₂

(Count as correct if anyone changed the order of elements if subscripts are correct.)

400

This is the empirical formula of a substance that is composed of 1.11g Se and 1.61g F.

What is . . . 

SeF₆

500

The empirical formula for a substance that is made of 48.6% carbon, 8.16% hydrogen, and 43.2 % oxygen.

What is . . .

C₃H₆O₂

Molecular Formulas

100

True or false: A molecular formula shows the ratio of elements that actually exist.

What is . . .

True

200

Of the following, which would be a molecular formula based on the empirical formula HO :

H₂O       NaOH      H₂O₂

What is . . .

H₂O₂

300

This would be the molecular formula for a compound with a molar mass of 88.12g/mol and an empirical formula of C₂H₄O

What is . . .

C₄H₈O₂

400

This would be the molecular formula for a compound that has an empirical formula of P₂O₅ and a molar mass of 283.88g

What is . . .

P₄O₁₀

500

Take your time on this: A compound contains only nitrogen and oxygen is 30.4% nitrogen by mass and 69.6% oxygen by mass. This is the molecular formula of the compound if the molar mass is 92 g/mol.  Hint: First determine the empirical formula and then find the molecular formula.

What is . . .

N₂O₄