Question

A brick has a mass of 4.0kg and the earth has a mass of 6.0*10^27g.
what is the mass of 1 mole of bricks?
how many moles of bricks have a mass equal to the mass of the earth?

Answer 1

Answer:

$\boxed{\text{6.022 \times 10^{23} kg; 2.5 \times 10^{-4} \ mol}}$

Explanation:

1. Mass of 1 mol of bricks

$m = 6.022 \times 10^{23}\text{ bricks} \times \dfrac{\text{4.0 kg}}{\text{ 1 brick}} = 2.4 \times 10^{24}\text{ kg}\\\\\text{The mass of 1 mol of bricks is }\boxed{\textbf{2.4 \times\mathbf{10^{24}} kg}}$

2. Number of moles

(a) Convert grams to kilograms

$6.0 \times 10^{24}\text{ g} = 6.0 \times 10^{21}\text{ kg}$

(b) Convert kilograms to moles

$n = 6.0 \times 10^{21}\text{ kg} \times \dfrac{\text{1 mol bricks }}{2.4 \times 10^{24}\text{ kg}} = \text{0.0025 mol bricks}\\\\\text{The mass of the Earth equals the mass of }\boxed{\textbf{0.0025 mol of bricks}}$

Answer 2

Answer: The mass of 1 mole of brick is $24.088\times 10^{26}g$ and the moles of brick having same mass as earth is 2.49 moles.

Explanation:

We are given:

Mass of a brick = 4.00 kg = 4000 g  (Conversion factor:  1 kg = 1000 g)

According to mole concept:

$6.022\time 10^{23}$ number of atoms are contained in 1 mole of an atom.

As, mass of 1 brick is 4000 g

So, mass of $6.022\times 10^{23}$ number of bricks will have = $\frac{4000}{1}\times 6.022\times 10^{23}=24.088\times 10^{26}g$

Now, calculating the moles of brick having the mass equal to the mass of Earth.

Mass of Earth = $6\times 10^{27}g$

To calculate the moles of bricks, we apply unitary method, we get:

$24.088\times 10^{26}g$ of mass is occupied by 1 mole of brick

So, $6.0\times 10^{27}g$ of mass will be occupied by $\frac{1}{24.088\times 10^{26}}\times 6.0\times 10^{27}=2.49moles$

Hence, the mass of 1 mole of brick is $24.088\times 10^{26}g$ and the moles of brick having same mass as earth is 2.49 moles.