How much heat is needed to change the temperature of the gas?

Question

A rigid container holds 0.740 g of hydrogen gas. How much heat is needed to change the temperature of the gas?

I know that from 50 K to 100 K its 231 J

and from 250 K to 300 K its 385 J

but what is it from 550 K to 600 K?

and from 2250 K to 2300 K ?

below is my work so far...what am i doing wrong?

work done by gas = dW = P dV = 0

dQ = dU = n Cv * dT

n = gram moles of H2

.740gram = (1/2)*0.740 = 0.37 moles = n

dT = 100 - 50 = 50 K

Cv = sp heat at const volume = 5R/2

dQ = dU = 0.37*(5*8.314/2)*50

dQ = 311.77 J

molecular weight of H2 is 2 * 1.00794 = 2.01588 grams per mole

.700 g of hydrogen gas will have .740/ 2.016 = .367

moles

(.367) (20.785) (50) = 381

Q= nCv (Tf - Ti)

Answer 1

The heat required for 550 K to 600 K is the same as needed for 250 K to 300 K. Heat required for 2250 K to 2300 K, estimated energy required is about 505 J. One thing I found in your answer is the Cv is about 27.5.