Question

A sample of gaseous nitrogen is heated with an electrical coil. If 235 Joules of energy are added to a 14.8 gram sample and the final temperature is 39.7°C, what is the initial temperature of the nitrogen? C. Answer:

Answer 1

Calculation of the initial temperature of nitrogen gas:

Specific heat capacity of nitrogen gas, C_p = 1.040 j / g.K

Mass of nitrogen gas, m = 14.8 grams

The amount heat, q = 235 joules

delta T = (T₂ - T₁)

Initial temperature, T₁ = ?

Final temperature, T₂ = 39.7 ^oC

The amount heat, q = m * C_p * delta T

                                 235 = 14.8 * 1.040 * ( 39.7 -T₁ )

                                 T₁ = 24.4^oC

Initial temperature, T₁ = 24.4^oC

Calculation of the final temperature of solid diamond:

Specific heat capacity of solid diamond, C_p = 0.5091 j / g.K

Mass of nitrogen gas, m = 13.8 grams

The amount heat, q = 124 joules

delta T = (T₂ - T₁)

Initial temperature, T₁ = 20.4 ^oC

Final temperature, T₂ = ?

The amount heat, q = m * C_p * delta T

                                 124 = 13.8 * 0.5091 * ( T₂ - 20.4 )

                                 T₂ = 38.1^oC

Final temperature, T₂ = 38.1^oC