## 8.53

donnanguyen1d
Posts: 64
Joined: Fri Sep 29, 2017 7:04 am

### 8.53

8.53 The reaction of 1.40 g of carbon monoxide with
excess water vapor to produce carbon dioxide and hydrogen gases in a bomb calorimeter causes the temperature of the calorimeter assembly to rise from 22.113 C to 22.799 C. The calorimeter assembly is known to have a total heat capacity of 3.00 kJ·(C)-1 (a) Write a balanced equation for the reaction. (b) Calculate the internal energy change, deltaU, for the reaction of 1.00 mol CO(g).

For Part B, it asks for the reaction of 1.00 mol of CO, why do we use 1.40g of CO to calculate for the answer then?

Lourick Bustamante 1B
Posts: 50
Joined: Wed Nov 16, 2016 3:02 am

### Re: 8.53

You use the value of 1.40 g CO because you know the change in temperature caused by this amount of CO, and so you can then set a ratio to get the change in temperature for one mole of CO (28 g CO). That being said, you could take 1.40 g CO/.686°C = 28.0 g CO/ΔT and cross-multiply to solve for ΔT to get 13.72°C for one mol of CO. Then you can just take all your calculated values and plug them into the equation ΔU=(3/2)nRΔT.

Christy Zhao 1H
Posts: 50
Joined: Fri Sep 29, 2017 7:07 am

### Re: 8.53

How do you know to use the equation $\Delta U=(3/2)nR\Delta T$ ?

melissa carey 1f
Posts: 53
Joined: Fri Sep 29, 2017 7:06 am

### Re: 8.53

Christy Zhao 1H wrote:How do you know to use the equation $\Delta U=(3/2)nR\Delta T$ ?

Since its in a bomb calorimeter, the volume is held constant, so c=3/2R for an ideal gas.

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