Question

Calculate the number of gram atoms present in
(i)640 gram of sulphur.
(ii)360 gram of magnesium
(iii)320 gram of oxygen​

Answer 1

Answer:-

(i) 20 gram atoms.

(ii) 15 gram atoms.

(iii) 20 gram atoms.

Explanation:-

Note : Number of gram atoms is equal to the number of moles.

For number (i) :-

Molar mass of Sulphur (S) = 32 g/mol

No of gram atoms :-

= Given Mass/Molar mass

= 640/32

= 20

For number (ii) :-

Molar mass of Magnesium (Mg) = 24 g/mol

No of gram atoms :-

= Given Mass/Molar mass

= 360/24

= 15

For number (iii) :-

Molar mass of Oxygen (O) = 16 g/mol

No of gram atoms :-

= Given Mass/Molar mass

= 320/16

= 20

Answer 2

Answer:

Given :-

640 g of Sulphur

360 g of magnesium

320 g of oxygen

To Find :-

Number of gram atoms

Solution :-

Since we are given with mass.

1]

We know that

Molar mass in Sulphur = 32

Finding no. of moles

$\bf \pink{No. \: of \: moles = \dfrac{Mass}{Molar \: Mass}}$

$\sf \: \dfrac{640}{32}$

$\sf \: 20 \: gram$

2]

Molar mass in magnesium = 24

$\bf \pink{No. \: of \: moles = \dfrac{Mass}{Molar \: Mass}}$

$\sf \: \dfrac{360}{24}$

$\sf \: 15\: gram$

3]

Molar mass in Oxygen = 16

$\bf \pink{No. \: of \: moles = \dfrac{Mass}{Molar \: Mass}}$

$\sf \: \dfrac{320}{16}$

$\sf \: 20 \: gram$