41. One mole of a monatomic ideal gas is mixed with one mole of a diatomic ideal gas. Assuming no chemical reaction occurs and they reach thermal equilibrium, what is the molar specific heat at constant volume of this gas mixture? (assume R is the ideal gas constant) (A) 1.5 R (B) 2.0 R (C) 2.5 R (D) 3.5 R