The activity of pure hydrogen gas at 1000°C and 5 atm. pressure.

What is enthalpy?

A. Heat of any system

B. entropy of any system

C. phase of any system

D. none of these

What are the types of entropy?

A. Thermal entropy

B. Configurational entropy

C. Both A and B

D. None of these

Single component system is called

A. ternary system

B. binary system

C. unary system

D. none of these

The specific heat (C_p) of pure iron expressed in J/(mol.K) as a function of temperature T (in K) is given as:
C_p = 17.49 + 24.77 × 10^-3 T
What is the change in the enthalpy of pure iron (in J/mol) when it is heated from 25°C to 700°C?

A. 11200

B. 22400

C. 28600

D. -32500