JEE Advance - Chemistry (1991 - No. 11)

Calculate the volume occupied by 5.0 g of acetylene gas at 50^oC and 740 mm pressure.

4.87 L

5.00 L

5.23 L

5.50 L

4.50 L

Mol. mass of acetylene (C₂H₂) = 26 ; T = 50 + 273 = 323 K

$$\therefore$$ 5 g acetylene $$ = {5 \over {26}}$$ moles. Let V be the volume occupied by 5 g of C₂H₂

Applying PV = nRT, we get

$${{740} \over {760}} \times V = {5 \over {26}} \times 0.082 \times 323$$

or $$V = {{5 \times 0.082 \times 323 \times 760} \over {26 \times 740}}L = 5.23\,L$$.