Question

Under the same conditions of temperature and pressure you collect 2L of carbon dioxide, 3L of chlorine, 5L of hydrogen, 4L of nitrogen and 1L of sulphur dioxide. In which gas sample will there be :
a. The greatest number of molecules. 
b. The least number of molecules.
Justify your answer.

Answer 1

Calculation of number of molecules in each gas sample:
(i) 2L of carbon dioxide :
22.4L of carbon dioxide has = 6.023 x 10²³ molecules
2L of carbon dioxide will have = 6.023 x 10²³ x 2/22.4
= 0.5377 x 10²³ molecules
(ii ) 3L of chlorine :
22.4L of chlorine has = 6.023 x 10²³ molecules
3L of chlorine will have = 6.023 x 10²³ x 3/22.4
= 0.8066 x10²³molecules
(iii ) 5L of hydrogen :
22.4L of hydrogen has = 6.023 x 10²³ molecules
5L of hydrogen will have = 6.023 x 10²³ x 5/ 22.4
= 1.34 x10²³ molecules
(iv) 4L of nitrogen :
22 .4 L of nitrogen has = 6.023 x 10²³ molecules
4 L of nitrogen will have = 6.023 x 10²³ x 4/ 22 .4
= 1.07 x10²³ molecules
(v) 1L of sulphur dioxide :
22.4L of sulphur dioxide has = 6.023 x 10²³ molecules
1 L of sulphur dioxide will have = 6.023 x 10²³ x 1/22.4
= 0.27 x10²³ molecules
From the above calculation of number of molecules in different gases we can conclude that the :
(a)The greatest number of molecules are present in 5L of hydrogen gas sample.
(b )The least number of molecules is in 1L of sulphur dioxide gas sample.