A Biology Experiment

Question

A biology experiment requires the preparation of a water bath at 37.0 Celsius (body temperature). The temperature of the cold tap water is 22.0 Celsius, and the temperature of the hot tap water is 55.0 Celsius. If a student starts with 90.0 g cold water, what mass of hot water must be added to reach 37.0 Celsius?

Answer 1

Hello!

The formula you want to use is:

M1(T1-Tfinal)=M2(Tfinal-T2)

Where

M1 = the mass of the hot water

T1 = the temperature of the hot water

M2 = the mass of the cold water

T2 = the temperature of the cold water

Tfinal = the final water temperature

At this point, it's easiest to substitute our values and we get:

M1(55.0-37.0)=90(37.0-22.0)

Resolving the parentheses, we get:

M1(18.0)=90(15.0)

We then isolate M1 by dividing each side of the equation by 18.0

M1=(90×15.0)/18.0

Remember, once again, to calculate the inside of the parentheses first, and then divide, and you will have the answer.