How many grams of water could be heated from 25 degrees Celsius to 100 degrees Celsius upon absorption of 4.22 kcal of heat?

Answer 1

E = mass x specific heat x Δ°t (temperature change)

------------------ Energy

specific heat * temperature change = mass

Δ°t = new temperature - original temperature

In order to calculate the mass of water able to be heated, we must divide the given energy by the result of specific heat times temperature change. Before proceeding to do such, we must calculate the temperature change, as well as convert cal to joules. It is also important to know that water's specific heat is 4.184 J/g°C.

1. Calculate temperature change.

Δ°t = 100°C-25°C

Δ°t= 75°C

2. Convert kcal to joules (multiply kcal * 103 * 4.184 joules [J]). (kcal --> joules)

Joules = 4.22 kcal x 103 cal x 4.184 J/g°C = 17656.48 Joules

------------------------ 1 kcal ------ 1 cal

3. Find mass.

Mass = 17656.48J

(4.184J/g°C * 75°C) = 56.3g