Mass, Moles, Molecules, and Volumes Worksheet
1) How many molecules are there in 24 grams of FeF
3
?
2) How many molecules are there in 450 grams of Na
2
SO
4
?
3) How many grams are there in 2.3 x 10 24 atoms of silver?
4) How many grams are there in 7.4 x 10 23 molecules of AgNO
3
?
5) How many grams are there in 7.5 x 10 23 molecules of H
2
SO
4
?
6) How many molecules are there in 122 grams of Cu(NO
3
)
2
?
7) How many grams are there in 9.4 x 10 25 molecules of H
2
?
8) How many molecules are there in 230 grams of CoCl
2
?
Adapted from: © 2000 Cavalcade Publishing – All Rights Reserved For chemistry help, visit http://www.chemfiesta.com

9) How many molecules are there in 2.3 grams of NH
4
SO
2
?
10) How many grams are there in 3.3 x 10 23 molecules of N
2
I
6
?
11) How many molecules are there in 200 grams of CCl
4
?
12) How many grams are there in 1 x 10 24 molecules of BCl
3
?
13) How many grams are there in 4.5 x 10 22 molecules of Ba(NO
2
)
2
?
14) How many molecules are there in 9.34 grams of LiCl?
15) How many grams do 4.3 x 10 21 molecules of UF
6
weigh?
16) How many molecules are there in 230 grams of NH
4
OH?
Adapted from: © 2000 Cavalcade Publishing – All Rights Reserved For chemistry help, visit http://www.chemfiesta.com

17) How many grams of oxygen do you have in 11.207 L @STP?
18) How many molecules of ammonia gas (NH
3
) do you have, if you 78 grams of ammonia gas?
19) What volume of gas do I have @ STP if I have 8.5 moles?
20) What mass of chlorine gas do I have @ STP if I have 3.40 moles?
Adapted from: © 2000 Cavalcade Publishing – All Rights Reserved For chemistry help, visit http://www.chemfiesta.com

Moles, Molecules, and Grams Worksheet
– Answer Key
1) How many molecules are there in 24 grams of FeF
3
?
1.28 x 10 23 molecules
2) How many molecules are there in 450 grams of Na
2
SO
4
? 1.91 x 10 24 molecules
3) How many grams are there in 2.3 x 10 24 atoms of silver? 421 grams
4) How many grams are there in 7.4 x 10 23 molecules of AgNO
3
? 209 grams
5) How many grams are there in 7.5 x 10 23 molecules of H
2
SO
4
? 122 grams
6) How many molecules are there in 122 grams of Cu(NO
3
)
2
? 3.92 x 10 23 molecules
7) How many grams are there in 9.4 x 10 25 molecules of H
2
? 312 grams
8) How many molecules are there in 230 grams of CoCl
2
? 1.07 x 10 24 molecules
9) How many molecules are there in 2.3 grams of NH
4
SO
2
? 1.69 x 10 22 molecules
10) How many grams are there in 3.3 x 10 23 molecules of N
2
I
6
? 430 grams
11) How many molecules are there in 200 grams of CCl
4
? 7.82 x 10 23 molecules
12) How many grams are there in 1 x 10 24 molecules of BCl
3
? 195 grams
13) How many grams are there in 4.5 x 10 22 molecules of Ba(NO
2
)
2
? 17.1 grams
14) How many molecules are there in 9.34 grams of LiCl? 1.33 x 10 23 molecules
15) How many grams do 4.3 x 10 21 molecules of UF
6
weigh? 2.51 grams
16) How many molecules are there in 230 grams of NH
4
OH? 3.96 x 10 24 molecules
17) How many grams of oxygen do you have in 11 L @STP?
(11 L)(22.414 L/mol) = 0.5 mol O
2
Adapted from: © 2000 Cavalcade Publishing – All Rights Reserved For chemistry help, visit http://www.chemfiesta.com

(0.5 mol O
2
)(32 g/mol) = 16 g O
2
18) How many molecules of ammonia gas (NH
3
) do you have, if you 78 grams of ammonia gas?
1mole ammonia (NH
3
) = (1 x 14.0067 g/mol) + (3 x 1.0079 g/mol) =
17.0304 g/mol of NH3
Therefore, I have: (78 grams NH3)/(17.0304 g/mol) = 4.58 moles NH3
I can then calculate how many molecules I have based on Avagadro’s
Number 6.02 x 10 23 molecules/mole.
(4.58 moles)( 6.02 x 10 23 molecules/mole) = 2.75716 x 10 24
or 2.8 x 10 24 molecules when rounded to 2 significant digits.
19) What volume of gas do I have @ STP if I have 8.5 moles?
(22.414 l/mol)(8.5 mol) = 190.519 L or 190 L (rounded to 2 sig.dig.)
20) What mass of chlorine gas do I have @ STP if I have 3.40 moles?
1 mol Cl
2
= 2 x 35.453 g/mol = 70.906 g/mol Cl2
(3.40 mol Cl
2
)(70.906 g/mol Cl
2
) = 241 g Cl
2
(rounded to 3 sig dig)
Adapted from: © 2000 Cavalcade Publishing – All Rights Reserved For chemistry help, visit http://www.chemfiesta.com