Ch. 10 The Mole

1

100

How many particles are in each of the following?

CaO

2

200

How many molecules are in a mole?

6.022x10²³

300

How many atoms are in the following?
1.35mol of Hg

1.35mol (6.022x10²³molecules/1 mol)

(1 atom/1molecule)=8.130x10²³

400

1. How many moles are in the following?
   32.7 L of O₂

32.7L(1mol/22.4L)= 1.460mol

500

Calculate the percent composition of OH

mass O= 15.999;   H= 1.008

total= 17.007g

(15.999/17.007)*100%= 94.073% O

(1.008/17.007)*100%= 5.927%H

2

100

How many particles are in each of the following?

HgNO₃

5

200

How many liters are there at standard temperature and pressure if 1 mole of gas is present?

22.4L

300

How many atoms are in the following?
13mol of CN

13mol (6.022x10²³molecules/1 mol)

*(2atom/1molecule)=1.566x10²⁵

400

1. How many grams are in the following?
   32.7 L of H₂

32.7L(1mol/22.4L)(2.016g/1mol)=2.943g

500

Calculate the percent composition of Mn(OH)₄

mass Mn= 54.998;  O*4= 63.996;   H*4= 4.032

total= 123.026

(54.998/123.026)*100%= 44.704% Mn

(63.996/123.026)*100%= 51.989% O

(4.032/123.026)*100%= 3.277%H

3

100

How many particles are in each of the following?

P₂Si₃H₈

13

200

Given an empirical formula is the smallest whole number ratio of a molecule which of the following is an empirical formula?

A) C₅H₁₀O₅

B) C₆H₁₂O₂

C) C₅₅H₇₂N₄O₅

C

300

How many moles are in the following?
6.022x10²⁵ atoms S

6.022x10²⁵atoms(1molecule/1 atom)

*(1 mol/6.022x10²³molecules)=100 mol S

400

How many grams are in the following?
19.3 L of O₂C₂H₈

19.3L(1mol/22.4L)(64.084g/1mol)=55.215g

500

Calculate the percent composition of Mg(OH)₂.

mass Mg= 24.305;  O*2= 31.998;   H*2= 2.016

total= 58.319g

(24.305/58.319)*100%= 41.676% Mg

(31.998/58.319)*100%= 54.867% O

(2.016/58.319)*100%= 3.457%H

4

100

How many particles are in each of the following?

H₂O

3

200

Given an empirical formula is the smallest whole number ratio of a molecule which of the following is not an empirical formula?

A) C₅H₁₀O₅

B) C₆H₁₁O₂

C) C₅₅H₇₂N₃O₅

A

300

How many moles are in the following?
1.35x10¹⁹ atoms He

1.35x10¹⁹atoms(1molecule/1 atom)

*(1 mol/6.022x10²³molecules)

=2.242x10^-5mol He

400

What is the percent composition of the compound that occurs when 2.70g of aluminum combines with oxygen to form 5.10g of aluminum oxide?

5.1g AL₂O₃ - 2.7g Al = 2.4g O

(2.7g/5.1g)*100% = 52.941% Al

(2.4g/5.1g)*100% = 47.059% O

500

Determine the empirical formula for a compound that is 63.52% Fe and 36.48% S.

mass Fe=55.845; S=32.06

63.52/55.845 =1.137

36.48/32.06 =1.137

Divide by smallest gives both being 1. =FeS

5

100

How many particles are in each of the following?

O₂

2

200

Given an empirical formula is the smallest whole number ratio of a molecule which of the following is not an empirical formula?

A) N₃H₉O₆

B) C₅H₁₂O₂

C) C₅H₇N₄O₅

A

300

How many moles are in the following?
15.9 L of NO₃

15.9L(1mol/22.4L)= 0.710mol

400

What is the percent composition of the compound that occurs when 7.2g of aluminum combines with oxygen to form 18.3g of aluminum oxide(Al and O)?

18.3g AL₂O₃ - 7.2g Al = 11.1g O

(7.2g/18.3g)*100% = 39.344% Al

(11.1g/18.3g)*100% = 60.658% O

500

Determine the empirical formula for a compound that is 71.72% Cl, 16.16% O, and 12.12% C.

mass Cl=35.45; O=15.999; C=12.011

71.72/35.45 =2.023

16.16/15.999 =1.010

12.12/12.011 =1.009

Divide by smallest gives Cl~2; O~1; and C=1.

Cl₂OC