Question

1.   Choose the correct answer(s) to complete the following statement: One mole of oxygen (O_2) gas is equivalent to _____________________.

I. 6.022 × 10²³ molecules of oxygen
II. 6.022 × 10²³ atoms of oxygen
III. one mole of oxygen atoms
IV. two moles of oxygen atoms

2.

50.0 g of Cl₂ contains ________ mol Cl₂.

a. 0.705

b.1.41

c. 4.24 × 1023

d. 1775

e. 50.0

3.

The number of grams in 0.350 mol of Na is

a. 11.0.

b. 8.05.

c. 65.7.

d. 0.350.

e. 23.0.

4.

If a tablet of acetaminophen, C₈H₉NO₂, weighs 324 mg, how many moles are there in the tablet?

a. 466

b. 4.89 × 104

c.2.15 × 10-3

d. 48.9

e. 2.15

5.

How many molecules are present in 4.25 mol of CCl₄?

a. 653.69 molecules

b. 2.56 × 1024 molecules

c.153.81 molecules

d.3.69 × 10-23 molecules

e. 9.26 × 1024 molecules

6.

A thimble of water contains 4.0 × 10²¹ molecules. The number of moles of H₂O is

a.2.4 × 1023.

b. 6.6 × 10-3.

c. 2.4 × 10-23.

d. 2.4 × 1045.

e. 6.6 × 10-23.

7.

42.0 g Cl₂ contains ________ molecules Cl₂.

a. 6.75 × 1023

b. 0.592

c. 3.57 × 1023

d. 1.78 × 1023

e. 1.18

8.

Acid rain forms in the upper atmosphere by the reaction of sulfur trioxide with water forming sulfuric acid. Calculate the mass in grams of 5.65 × 10²¹ molecules of SO₃.

a.1.17 × 10-4 g

b.0.751 g

c. 2.72 × 1047 g

d. 1.17 g

e. 0.0751 g

Answer 1