Transcript Document

Pg. 323
1. Zinc (Zn) is used to form a corrosioninhibiting surface on galvanized steel. Determine
the number of Zn atoms in 2.50 mol of Zn.
2.50 mol Zn 6.02 x 1023 atoms = 1.51 x 1024
1 mol Zn
atoms of Zn
2. Calculate the number of molecules in 11.5 mol
of water (H20).
23
6.02
𝑥
10
𝑚𝑜𝑙𝑒𝑐𝑢𝑙𝑒𝑠 𝐻2 𝑂
11.5 mol 𝐻2 𝑂 x
1 𝑚𝑜𝑙 𝐻2 𝑂
= 6.92 x1024 molecules 𝐻2 𝑂
Pg. 324
5. How many moles contain each of the following?
a)5.75 x 1024 atoms Al
b)2.50 x 1020 atoms Fe
a) 5.75 𝑥
1024 𝑎𝑡𝑜𝑚𝑠
1 𝑚𝑜𝑙 𝐴𝑙
𝐴𝑙 𝑥
6.02 𝑥 1023 𝑎𝑡𝑜𝑚𝑠 𝐴𝑙
= 9.55 𝑚𝑜𝑙 𝐴𝑙
20
b) 2.50 𝑥 10 𝑎𝑡𝑜𝑚𝑠 𝐹𝑒 x
1 𝑚𝑜𝑙 𝐹𝑒
6.02 𝑥 1023 𝑎𝑡𝑜𝑚𝑠 𝐹𝑒
= 4.15 𝑥 10−4 𝑚𝑜𝑙 𝐹𝑒
Pg. 328
15. Determine the mass in grams of each of the
following:
a) 3.57 mol Al b) 42.6 mol Si
a) 3.57 𝑚𝑜𝑙 𝐴𝑙 x
27.0𝑔 𝐴𝑙
1 𝑚𝑜𝑙 𝐴𝑙
= 96.4 g Al
b) 42.6 𝑚𝑜𝑙 𝑆𝑖 x
28.1 𝑔 𝑆𝑖
1 𝑚𝑜𝑙 𝑆𝑖
= 1.20 𝑥 103 𝑔 𝑆𝑖
Pg. 329
17. Determine the number of moles in each of the
following.
a) 25.5 g Ag
b) 300.0 g S
a) 25.5 𝑔 𝐴𝑔 x
1 𝑚𝑜𝑙 𝐴𝑔
107.9 𝑔 𝐴𝑔
= 0.236 mol Ag
b) 300.0 𝑔 𝑆 x
1 𝑚𝑜𝑙 𝑆
32.1 𝑔 𝑆
= 9.35 mol S
Pg. 331
19. How many atoms are in each of the following
samples?
a) 55.2g Li 1 mol Li 6.02 x 1023 atoms
6.9 g Li
1 mol
= 4.8 x 1024 atoms
b) 0.230 g Pb1 mol Pb 6.02 x 1023 atoms
207.2 g Pb
1 mol
= 6.68 x 1020 atoms
c) 11.5g Hg 1 mol Hg 6.02 x 1023 atoms
200.6 g Hg
1 mol
= 3.45 x 1022 atoms
Pg. 331
20. What is the mass in grams of each of the
following?
1 𝑚𝑜𝑙 𝐵𝑖
24
a)6.02 x10 atoms Bi
23
6.02 𝑥 10
= 10.0 mol Bi
b)1.00
x1024
209.0 𝑔 𝐵𝑖
1 𝑚𝑜𝑙 𝐵𝑖
atoms Mn
= 1.66 mol Mn
𝑎𝑡𝑜𝑚𝑠 𝐵𝑖
= 2.09 x 103 g Bi
1 𝑚𝑜𝑙 𝑀𝑛
6.02 𝑥 1023 𝑎𝑡𝑜𝑚𝑠 𝑀𝑛
54.9 𝑔 𝑀𝑛
1 𝑚𝑜𝑙 𝑀𝑛
= 91.1 g Mn
Pg. 331
20. What is the mass in grams of each of the
following?
1 𝑚𝑜𝑙 𝐻𝑒
22
c) 3.40 x10 atoms He
23
6.02 𝑥 10
= 0.0565 mol Bi
d) 1.50 x
1015
= 2.49 x
10-9
4.0𝑔 𝐻𝑒
1 𝑚𝑜𝑙 𝐻𝑒
atoms N
mol N
𝑎𝑡𝑜𝑚𝑠 𝐻𝑒
= 0.226 g He
1 𝑚𝑜𝑙 𝑁
6.02 𝑥 1023 𝑎𝑡𝑜𝑚𝑠 𝑁
14.0𝑔 𝑁
1 𝑚𝑜𝑙 𝑁
= 3.49 x 10-8 g N
Pg. 331
20. What is the mass in grams of each of the
following?
e)1.50 x 10
= 2.49 x
15
10-9
atoms U
mol U
1 𝑚𝑜𝑙 𝑈
6.02 𝑥 1023 𝑎𝑡𝑜𝑚𝑠 𝑈
238.0𝑔 𝑈
1 𝑚𝑜𝑙 𝑈
= 5.93 x 10-7 g U