Question

Question 9 What is the mass of: (a) 0.2 mole of oxygen atoms? (b) 0.5 mole of water molecules?​

Answer 1

Question: What is the mass of 0.2 mole of oxygen atoms?

We have been given that mass of 0.2 mole of oxygen atoms.To solve this question, we have a formula which is given below.

• Mole = Mass(g) ÷ Atomic mass of atom

Step: Put the obtained values in formula.

Mole = Mass(g) ÷ Atomic mass of atom

0.2 = Mass ÷ 16

Mass = 0.2 mol × 16gmol^-1

Mass = 0.2 × 16 g

Mass = 3.2 g

Question: What is the mass of 0.5 mole of water molecules?

We have been given that 0.5 mole of water molecules. To solve this question, we have a formula which is given below.

• Mole = Mass(g) ÷ Atomic mass of atom

Step: Put the obtained values in formula.

Mole = Mass(g) ÷ molecular mass

0.5 = Mass ÷ 18 g mol^-1

Mass = 0.5 mol × 18 g mol^-1

Mass = 0.5 × 18 g

Mass = 9 g

Answer 2

Answer:

Explanation:

Answer 1

Mass of 1 mole of oxygen atoms = 16 g

Number of moles = 0.2 mole

Mass of oxygen = ??

Mass of water taken = no.of moles × moler mass of oxygen

Mass = 16 × 0.2

Mass = 3.2 g

Hence, mass of oxygen atoms is 3.2 grams.

Answer 2

(b) Mass of 1 mole of water molecule = 18 g

Number of moles = 0.5 mole

Mass of water = ??

Mass of water taken = no.of moles × moler mass of water

Mass = 0.5 × 18

Mass = 9 g

Hence, the mass of 0.5 mole of water is 9 g.