## 8.91

Janine Chan 2K
Posts: 71
Joined: Fri Sep 29, 2017 7:04 am

### 8.91

In the textbook, the question states that it takes 10.5 hours to reach 5C, but the solution manual uses 10 h. Is this a typo or am I missing something? I used these equations (4.184)(150 g)(5C - 0C)= 3135 J for 150 g and then I did ($\frac{3135 J}{150 g}*\frac{18.02 g}{1 mol}*\frac{1 kJ}{1000 J}*\frac{10.5 h}{0.5 h} = 7.91 kJ/mol$

Nickolas Manipud 1C
Posts: 60
Joined: Fri Sep 29, 2017 7:07 am

### Re: 8.91

Wassup Janine
You want to find how long it takes for ice to melt. The question says ice takes 10.5 h to reach 5 degrees Celsius and that the water at a liquid state at 0 degrees Celsius takes 0.5 h to reach 5 degrees Celsius. Therefore, the remaining 10.0 h must be from the ice melting. (10.5 - 0.5 = 10 h for the ice to melt).