The mole

mole/mass

100

What is the mass of 14.5 moles of hydrogen peroxide (H₂O₂)?

493 g

200

Find the number of moles of argon in 452 g of argon.

11.31 moles

300

Find the mass in grams of 2.23 moles of Fluorine gas

84.74 g F₂

400

What is the mass of 5 moles of Fe₂O₃?

798.5 g

500

How many moles in 28 grams of CO₂?

0.64 moles

Mole/particle

100

How many moles are 5.92x10⁷¹ gold atoms?

9.83 x 10⁴⁷

200

How many moles of magnesium are in 3.01 x 10²² atoms of magnesium?

0.05 moles

300

How many molecules are there in 0.655 moles C₆H₁₄?

3.94 x1023

400

How many molecules are there in 4.00 moles of glucose, C₆H₁₂O₆?

2.41 x 10²⁴ molecules

500

How many moles of H₂SO₄ do you have if you have 6.02 x 10²³ atoms of oxygen?

0.25 moles

2 Step

100

What is the mass in grams of 1.20 x 10²⁵ atoms of phosphorous?

6.17 g

200

Find the mass, in grams, of 1.00 x 10²³ molecules of N2.

4.65 g

300

How many grams does 5.60 x 10²² molecules of silicon dioxide weigh?

5.59 g

400

What is the volume of 1.2 grams of water vapor at standard temperature and pressure (STP)?

1.49 L

500

Calculate the number of atoms of sodium sulfate present in a 20.0 gram sample.

5.93 x 1023 atoms

Empirical/%

100

Calculate the percent composition by mass of the elements in sodium carbonate, Na₂CO₃.

Na: 43.4 %

C: 11.3%

O: 45.3 %

200

Calculate the percent composition by mass of Carbon in Mg(C₂H₃O₂)₂

33.7%

300

An organic compound is 68.54% carbon, 8.63% hydrogen, and 22.83% oxygen. What is the empirical formula of the compound?

C₄H₆O

400

Strychnine, a deadly poison, has a percentage composition of 75.42% carbon, 6.63% hydrogen, 8.38% nitrogen, and the balance oxygen. What is the empirical formula of strychnine?

C₂₁H₂₂N₂O2

500

A sample of a substance is determined to be composed of 0.89 grams of potassium, 1.18 grams of chromium, and 1.27 grams of oxygen. Calculate the empirical formula of this substance

K₂Cr₂O₇

Combustion/hydrate

100

Name the hydrate: Na₂SO₃ * 5 H₂O

Sodium Sulfite pentahydrate

200

A 1.50 g sample of hydrocarbon undergoes complete combustion to produce 4.40 g of CO₂ and 2.70 g of H₂O. What is the empirical formula of this compound?

CH₃

300

During lab, 1.04 g of NiSO₄ x H₂O were heated. After heating, only 0.61 g of NiSO₄ remained. What was the formula of the original hydrate?

NiSO₄ x 6H₂O

400

Vitamin C, M= 176.12 g/mol, is a compound of composed of carbon, hydrogen, and oxygen. Vitamin C is found in many natural sources especially citrus fruits. When a 1.000-g sample of vitamin C is burned in a combustion apparatus 1.50 g of CO₂ and 0.410 g of H₂O are produced. What is the empirical formula of Vitamin C?  What is the molecular formula of Vitamin C?

C₃H₄O₃

C₆H₈O₆

500

A hydrate of magnesium chloride is present and the following data is collected:

mass of crucible = 22.130 grams

mass of crucible + hydrate = 25.290 grams

mass of crucible and contents after heating = 23.491 grams

What is the complete formula of this hydrate?

MgCl₂ •7H₂0