The specific heat capacity of rubidium is 0.360 J/g°C. A sample of rubidium absorbs 40.0 kJ

when heated from 12.5 °C to 38.0 °C. Calculate the mass of the rubidium sample.

4.36 kg rubidium.

Explanation: Quantity of heat is calculated by multiplying the mass of substance by the specific heat capacity and the change in temperature.

That is; Q = mcΔT

We are given;

Quantity of heat = 40.0 kJ or 40,000 Joules

Mass of rubidium = 0.360 J/g°C

Change in temperature, ΔT = 38.0°C - 12.5°C

= 25.5°C

We are required to calculate the mass of rubidium

From the formula; Q = mcΔT

mass = Q : cΔT

= 40,000 : (0.360 J/g°C * 25.5°C)

= 4,357.30 g

= 4.36 kg

Therefore, the mass of 4.36 kg rubidium.