Question

❤️❤️Hey mates ❤️❤️

!!!! convert the following into moles -

1. 72 g of H2O

2. 22 g of CO2

!!!! if chlorine - 35 is present in nature in 75% and chlorine -37 is present in. 25% . calculate the average atomic mass of chlorine .

!!!! if the average atomic mass of oxygen is 16.2 u , calculate the percent of Oxygen - 16 and Oxygen - 18 present in nature .​

Answer 1

${\huge {\mathfrak {Answer :-}}}$

➡️ $<b>First question </b>$

✨ 1

Molar mass of H2O = 2 + 16 = 18 g.

Hence, we have,

18 g of H20 = 1 mole.

1 g of H20 = 1/18 mole.

72 g of H20 = 1/18 * 72 = 4 mole.

✨ 2

Molar mass of CO2 = 12 + 32 = 44 g.

Hence, we have ,

44 g of CO2 = 1 mole

1 g of CO2 = 1/44 mole

22 g of CO2 = 1/44 * 22 = 0.5 mole

➡️ $<b>Second question </b>$

Cl - 35 is present in 75 %

Cl - 37 is present in 25 %

Average atomic mass of Cl is

= 75/100 * 35 + 25/100 * 37 u

= 105/4 + 37/4 u

= 142/4 u

= 35.5 u.

➡️ $<b>Third question </b>$

Let, O -16 is present in x %

O - 18 is present in (100 - x) %.

By condition,

x/100 * 16 + (100 - x)/100 * 18 = 16.2

Or, 16x + 1800 - 18x = 1620

Or, 2x = 180

Or, x = 90.

Hence, O - 16 is present in 90 %

O - 18 is present in (100 - 90) = 10 %

✨ That's it.. ✨