# Molar Specific Heat Homework: Calculating Change in Internal Energy

• Indy2424
In summary, 25.2 J of heat was added to an ideal gas at a constant pressure of 1.0 atm, causing its volume to change from 46.0 to 101.2 cm3. The internal energy of the gas changed by 19.6 J. The molar specific heat at constant pressure is the next question, which the student is struggling with and believes there may be a missing piece of information in the problem. They have attempted the problem multiple times but are unsure if their conversions and setup are correct. They are seeking help to solve the question.
Indy2424

## Homework Statement

Let 25.2 J of heat be added to a particular ideal gas. As a result, its volume changes from 46.0 to 101.2 cm3 while the pressure remains constant at 1.0 atm. By how much did the internal energy of the gas change?
19.6 J is the answer which i understand how to get the next question is

What is the molar specific heat at constant pressure?
I have tried so many different ways. I don't know if I am doing conversions wrong or not setting it up right. I am pretty sure all my conversions are right.

## 1. What is molar specific heat?

Molar specific heat is the amount of energy required to raise the temperature of one mole of a substance by one degree Celsius. It is measured in joules per mole Kelvin (J/molK).

## 2. How is molar specific heat different from specific heat?

Molar specific heat is the specific heat of a substance per mole, while specific heat is the specific heat of a substance per gram. Molar specific heat takes into account the molecular weight of a substance, whereas specific heat is independent of the amount of substance.

## 3. How do you calculate change in internal energy using molar specific heat?

The formula for calculating change in internal energy (ΔU) using molar specific heat is: ΔU = n x CΔT, where n is the number of moles, C is the molar specific heat, and ΔT is the change in temperature. This formula assumes constant pressure (i.e. no work is being done) and no phase changes.

## 4. What are the units for molar specific heat?

The units for molar specific heat are joules per mole Kelvin (J/molK). Sometimes, the units are given as calories per mole Kelvin (cal/molK), but these can easily be converted using the conversion factor 1 cal = 4.184 J.

## 5. How is molar specific heat determined experimentally?

Molar specific heat can be determined experimentally by measuring the amount of energy required to raise the temperature of a known mass of a substance by a known amount, and then using the formula C = q/(nΔT) to calculate the molar specific heat. Alternatively, it can also be measured using calorimetry, where the heat absorbed or released during a chemical reaction is measured and used to calculate the molar specific heat of the reacting substances.

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