## Exercise E35

Kellina Tran 2I
Posts: 50
Joined: Sat Jul 22, 2017 3:00 am

### Exercise E35

I believe that the formula for calculating percent change is the original subtracted from the result, divided by the original value. The original value in this problem should be the mass of hydroxyapatite, 502.31 g/mol, but the solutions manual divides the difference by the latter value of flourapatite instead (504.30 g/mol). Is this a mistake in the text, or am I doing something wrong? (It doesn't matter because both yield 0.39%, but I just want to make sure for future reference).

404995677
Posts: 82
Joined: Fri Sep 29, 2017 7:07 am

### Re: Exercise E35

Someone in my Discussion asked this question and my TA said that the equation for percent change is dividing by the original value. I believe the book had it wrong.

Cam Bear 2F
Posts: 60
Joined: Thu Jul 27, 2017 3:01 am

### Re: Exercise E35

Yes, percent change is found by doing [(Final Value minus Initial Value)/ Initial Value] times 100