Question

2 moles of an ideal monoatomic gas initially at 25°C
and 2 atm are heated at constant pressure to a
temperature of 100°C. Calculate AH.
5R
Given Cp = (R = 2Cal):
2
А. -750 Cal
B. 750 Cal
C. 0
D. 375 Cal​

Answer 1

Answer:

if's sioskshdjdkkkdkdkdndbndbdbdb

Answer 2

The amount of ΔH is 750 cal.

The amount of the gas (n) = 2 mole

Initial temperature = 25° C

                               = (25 + 273) K

                               = 298 K

Final temperature = 100° C

                              = (100+ 273) K

                              = 373 K

∴ Difference in temperature (dT) = (373 - 298) K

                                               = 75 K

We know, for a constant pressure,

According to the law of first rule of thermodynamics,

U = Q + W

where, U = Internal energy

            Q = Enthalpy = H

            W = Work done by gas

     ∴ H = U - W

⇒ H = nCp dT + n R dT [by putting values with sign]

⇒ H = n dT (Cp + R)

⇒ H = 2× 75 × 5 [As given in the question]

⇒ H = 150 × 5

⇒ H = 750 cal

The amount of H is 750 cal.