How much heat energy in joules must be supplied to 14 g of nitrogen at room temperature to raise its temperature by 40° C at constant pressure? (Mol. wt. of N2=28g,R= constant)

Question

How much heat energy in joules must be supplied to 14 g of nitrogen at room temperature to raise its temperature by 40° C at constant pressure? (Mol. wt. of N2=28g,R= constant) (A) 50 R (B) 60 R (C) 70 R (D) 80 R

Tardigrade Admin · Accepted Answer

Heat supplied at constant pressure Q=μ CpΔ T Here, Δ T=40 oC Cp=(7/2)R (for diatomic gases) Number of moles, μ =(14/28)=(1/2) ∴ Q=(1/2)× (7/2)R× 40=70R

Q. How much heat energy in joules must be supplied to 14 g of nitrogen at room temperature to raise its temperature by $40^{\circ} C$ at constant pressure? (Mol. wt. of $N_{2} = 28 g, R =$ constant)

50 R

60 R

70 R

80 R

Heat supplied at constant pressure $Q = μ C_{p} Δ T$ Here, $Δ T = 40^{o} C$ $C_{p} = \frac{7}{2} R$ (for diatomic gases) Number of moles, $μ = \frac{14}{28} = \frac{1}{2}$ $∴$ $Q = \frac{1}{2} \times \frac{7}{2} R \times 40 = 70 R$

Q. How much heat energy in joules must be supplied to 14 g of nitrogen at room temperature to raise its temperature by 40∘C at constant pressure? (Mol. wt. of N2​=28g,R= constant)