Question

(20%) Please calculate the H content (kg) in 1 cube meter of: 1.) liquid methane; 2.) water; 3.) Octane; and 4.) A1H3; and compare with Liquid H2, and comment on the results.

Answer 1

Solution:

(i)    H content in liquid methane of 1 m³ can be found out by knowing its density

            Density of 1 m³ liquid methane = 424 Kg/m³

Mass distribution of C and H in methane is 12:4 i.e. 3:1

So content of H in 1 m³ of liquid methane = 424×1 3= 141.33 Kg

424x1

(ii) Similarly H content in Water of 1 m³ can be found out by knowing its density

            Density of 1 m³ water = 997 Kg/m³

Mass distribution of O and H₂ in H₂O is 16:2 i.e. 8:1

So content of H in 1 m³ of liquid methane = 997×1 8= 124.625 Kg

997X1

(iii) H content in octane of 1 m³ can be found out by knowing its density

            Density of 1 m³ octane = 703 Kg/m³

Mass distribution of C and H in C₈H₁₈ (octane) is 96:18 i.e. 16:3

So content of H in 1 m³ of liquid methane = 703×3 16= 131.81 Kg

703x3 16

(iv) H content in AlH₃ of 1 m³ can be found out by knowing its density

            Density of 1 m³ AlH₃ = 1490 Kg/m³

Mass distribution of Al and H in AlH₃ is 27:3 i.e. 9:1

So content of H in 1 m³ of liquid methane = 1490×1 9= 165.56 Kg

1490X1

The density of liquid hydrogen is 71 Kg/m³ which is very less as compared to all the above mentioned elements.