WCH11 October 2022

9​​ A piece of copper is shown.

How many moles of copper atoms are there in this piece of copper?

[Density of copper = 8.96gcm–3]

A 0.675

B 1.48

C 6.05

D 54.2

ANSWER

D 54.2

Analysis of Option/Explanation

Step 1: Calculating Volume

volume of a cube=4×8×12

=384cm3

Step 2: Calculating Mass

density=massvolume

=8.96×384

mass=3440.64gram

Step 3:​​  Using ratio method

1 mole of Copper= 63.5 g

“X” moles of copper containing =​​ 3440.64g

Moles =​​ 3440.6463.5

=54.183 mol

Hence, Option D is the correct answer.