Mole & Mole Comparisons Review

Avogadro's Number

100

Avogadro's number equals...

6.022 x 10²³ particles = 1 mol

200

What is the unit of Avogadro's number?

particles

300

Avogadro's number is used to convert between ________ and ________.

particles and moles

400

How many particles are in 5.78 moles?

3.48 x 10²⁴ particles

500

How many moles are in 6.07 x 10²⁴ particles?

10.08 moles

Molar Mass

100

Molar mass is calculated by...

adding the atomic masses together

200

What are the units of molar mass?

g/mol

300

Molar mass is used to convert between ________ and ________.

moles and mass

400

How many grams are in 3.92 moles of water (H₂O)?

0.22 grams

500

How many moles are in 48.35 grams of sodium hydroxide (NaOH)?

1.21 moles

Mole Conversions

100

To convert moles into particles, you...

multiply by Avogadro's number

200

To convert particles into moles, you...

divide by Avogadro's number

300

To convert moles to mass (grams), you...

multiply by molar mass

400

To convert from mass (grams) to moles, you...

divide by molar mass

500

To convert from particles to mass (grams), you...

divide by Avogadro's number, then multiply by molar mass

Percent Composition

100

What is the formula for percent composition?

% composition = (atomic mass/molar mass) x 100

200

Find the percent composition of table salt (NaCl)?

39.34% sodium (Na) and 60.66% chlorine (Cl)

300

What is the percent composition of magnesium nitrate (Mg(NO₃)₂)? 

16.39% magnesium, 18.88% nitrogen, and 64.73% oxygen

400

How many grams of oxygen are in a 58.9 g sample of CO₂?

42.83 g

500

How many grams are present of each element in a 27.4 g sample of methane (CH₄)?

 20.51 g of carbon and 6.89 g of hydrogen

Molecular vs. Empirical

100

What is the main difference between molecular and empirical formulas?

Molecular formulas contain the real amounts, while empirical formulas are simplified to the lowest whole-number.

200

What is the empirical formula for butane (C₄H₁₀)?

C₂H₅

300

Find the molecular formula for benzene using the empirical formula, CH, and the molecular formula mass, 78.11 g/mol.

C₆H₆

400

Find the empirical formula of a compound that is 82.35% Nitrogen (N) and 17.65% Hydrogen (H).

NH₃

500

Find the empirical formula of a sample containing 23.48 g of sodium (Na) and 23.42 g of oxygen (O).

Na₂O₃