1) How many joules are required to change the temperature of 50g of water from 23.3C to 47.6C ?


2) If the specific heat of methanol is 2.51J/K-g, how many joules are necessary to rise the temperature of 50g of methanol form 20C to 60C ?


Solution (1+2) : by using "q= s.m.(t2-t1)" and direct substitution

its my thinking right ?


3) A 580-mL sample of water was cooled form 60C to 10C . How much heat was lost ?

4) Calculate the final temperature when 50 mL of water at 60C are added to 25mL of water at 25C ?

It will be the same solution of the above ? If it's same should I change the volume (mL) to (g) ?

(1 + 2). Yes, if all your involved units are the same, I mean, you use grams everywhere in these questions.

3. yes

4. yes, but be careful while substituting the values.