## Correct Answer For Test 1 Question 7

Hena Sihota 1L
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### Correct Answer For Test 1 Question 7

Question 7 on Test 1: In order to make iced-tea, a 50.0 g ice cube at 0.0 degrees Celsius is added to 250mL of tea at 20.0 degrees Celsius. What is the final temperature of the iced-tea once it has reached thermal equilibrium? Assume no heat is transferred to or from the surroundings.
I solved it using: (16675.91565J)+(50g)(4.184J.(degrees Celsius)-1.g-1)(Tf)=-(250g)(4.184J.(degrees Celsius)-1.g-1)(Tf-20 degrees Celsius)
The answer I got was: Tf=3.4 degrees Celsius
Is this the correct setup and answer?

Thuy-Anh Bui 1I
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### Re: Correct Answer For Test 1 Question 7

Yes, that is correct. The setup is qice=-qtea, which is nΔHfus + mCΔT = -mCΔT. You plugged in all the right numbers and got the correct final temperature.

Clarissa Molina 1D
Posts: 55
Joined: Fri Sep 29, 2017 7:04 am

### Re: Correct Answer For Test 1 Question 7

For the set up for this problem, how did you get 16675.91565 for the first part of the equation?

Erik Khong 2E
Posts: 50
Joined: Fri Sep 29, 2017 7:07 am

### Re: Correct Answer For Test 1 Question 7

Clarissa Molina 1D wrote:For the set up for this problem, how did you get 16675.91565 for the first part of the equation?

You're supposed to get the deltaH of fusion from the formula sheet and multiply it by the grams of ice, which you convert into moles:

(50g H2O/18.02 g/mol H20) * (6.01 kJ/mol) = 16.6759kJ or 16675.91565J.

Troy Tavangar 1I
Posts: 50
Joined: Fri Sep 29, 2017 7:04 am

### Re: Correct Answer For Test 1 Question 7

Yes that is correct.