Question

The heat released on combustion of 180 g of glucose is used for the isothermal expansion of an ideal gas. If the gas is expanded from 10 m3 at a constant external pressure of , the final volume occupied by the gas is:
(The enthalpy change in combustion of glucose is -2880 kJ/mol)

Answer 1

Answer:

ideal gas against a constant external pressure (P2), work done is ... of Volume 0.0083 m3, at a temperature of 300 K and a ... Q.5 How much heat is produced in burning a mole of

Answer 2

The heat released on combustion of 180 g of glucose is used for the isothermal expansion of an ideal gas. If the gas is expanded from 10 m³ at a constant external pressure of 4 × 10^5 N/m²

To find : The final volume occupied by the gas.

solution : enthalpy change in the combustion of glucose, Q = -2880 kJ/mol

no of moles of glucose = given weight/molecular weight

= 180g/180g/mol = 1 mole

now heat released in combustion of 1 mol of glucose , Q = -2880 kJ/mol × 1 mol = -2880 kJ

workdone , w = -P_ext ∆V

here, P_ext = 4 × 10^5 N/m²

V_i = 10 m³

for isothermal expansion, Q = w [ as internal energy change = 0 ]

⇒-2880 kJ = - 4 × 10^5 N/m² (V_f - 10m³)

⇒2880 × 10³ = 4 × 10^5 (V_f - 10 )

⇒7.2 = V_f - 10

⇒V_f = 17.2 m³

Therefore the final volume occupied by the gas is 17.2 m³.