When water is heated from 15 to 100 degrees Celsius, its internal energy increases by 178.8 kJ

We start the solution with a short note given.

So, given:

t1 = 15 ° C;

t2 = 100 ° C.

c = 4 200 J / kg * ° С.

Q = 178.8 kJ.

You need to find m -?

solution:

Let us apply to the solution the formula for calculating the amount of heat required to heat the body:

Q = c * (t2 – t1) * m.

Let us express the mass from the formula and get:

m = Q / c * (t2 – t1).

We have enough data to calculate the mass value, so all we have to do is plug it into the formula:

m = 178.8 kJ / 4 200 J / kg * ° С * (100 ° – 15 °) = 0.000501 kg = 0.501 g.