Random
Determining Formulas
Percent Composition
Molar Mass
Moles
100

The masses on the Periodic Table can be used with what two different units? 

grams and AMU (Atomic Mass Units)

100

Given that a 95.2g sample contains 40.8g of Carbon and 54.4g of Oxygen, determine the empirical formula.

Empirical Formula: Carbon Monoxide - CO

100

What is the simple equation used to determine percent composition?

Part / Whole x 100

100

What is the Molar Mass of NaCl?

58.5 g/mol

100

6.02 x1023 representative particles is known as 

Avogadro's Number

200
Subscripts always need to be these types of numbers.

Whole

200

Determine the Empirical Formula for a lactic acid that is 40.0% Carbon, 6.71% Hydrogen, and 53.3% Oxygen.

Empirical Formula

CH2O

200

What is the percent composition of sodium in NaCl? (Round to the nearest whole number)

39%

200

What is the molar mass of CO2?

44 g/mol

200

1 mole of a substance will contain 6.02 x1023 _____'s. THIS PROBLEM HAS MORE THAN ONE CORRECT ANSWER. GIVE EACH ANSWER FOR BONUS POINTS!

atoms, molecules, or formula units

300

True or False: The molecular formula will always be equal to or a multiple of the empirical formula.

True

300

What is the molecular formula for a compound with an empirical formula of C2OH4 and a molar mass of 44 g/mol. 

Molecular Formula:

C2OH4

300

What is the percent composition of copper in CuBr2? (Round to the tenth of a percent)

28.5%

300

What is the molar mass of NaOH?

40 g/mol

300

I want to convert atoms to moles. My friend tells me to multiply the number of atoms by 6.02 × 1023 atoms/mole. Is my friend correct?

No, you need to divide

400

Approximately what percent of gum is comprised of sugar?

a) 25%    b) 50%   c) 75%   d) 100%

b) 50%

400

Find the molecular formula for a compound with an empirical formula of CFBrO and a molar mass of 254.7 g/mol.

Molecular Formula:

C2F2Br2O2

400

What is the percent composition of bromine in CuBr2? (Round to the tenth of a percent)

71.5%

400

What is the molar mass of CaBr2?

200 g/mol

400

 How many atoms are in 2 moles of Na?

12.04*1023

500

How do Br, I, N, Cl, H, O, & F exist in nature? (Hint: what would there molecular formula be?)

As diatomic molecules!

Br2, I2, N2, Cl2, H2, O2, & F2

500

What are the empirical and molecular formulas of a compound containing 65.5% C, 5.5% H, and 29.0% O, and has a molar mass of 110 grams/mole?

This problem is worth 1000 points (all or nothing!)

Empirical Formula: C3H3O

Molecular Formula: C6H6O2

500

What is the percent composition of oxygen in NaOH? (Round to the nearest whole number)

40%

500

What is the molar mass of (NH4)2S?

68 g/mol

500

How many moles are in 18.06*1023 atoms of NaCl?

3 moles

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