CHE 105/110 Introduction to Chemistry - Exercises and Answers

1.

How many atoms are present in 4.55 mol of Fe?

1.

2.74 × 10²⁴ atoms

3.

How many molecules are present in 2.509 mol of H₂S?

3.

1.511 × 10²⁴ molecules

5.

How many moles are present in 3.55 × 10²⁴ Pb atoms?

5.

5.90 mol

7.

How many moles are present in 1.00 × 10²³ PF₃ molecules?

7.

0.166 mol

9.

9.

1. 28.086 g
2. 32.118 g
3. 94.195 g

11.

11.

1. 26.981 g
2. 101.959 g
3. 165.292 g

13.

What is the mass of 4.44 mol of Rb?

13.

379 g

15.

What is the mass of 12.34 mol of Al₂(SO₄)₃?

15.

4,222 g

17.

How many moles are present in 45.6 g of CO?

17.

1.63 mol

19.

How many moles are present in 1.223 g of SF₆?

19.

0.008374 mol

21.

How many moles are present in 54.8 mL of mercury if the density of mercury is 13.6 g/mL?

21.

3.72 mol