100.0 g of a 4.0^°c water is heated until it's temperature is 37 °c. if the specific heat of water is 4.18 J/g°c calculate the amount of heat energy needed to cause this rise in temperature.

We can use the heat equation,

Q = mcΔT

Where Q is the amount of energy transferred (J), m is the mass of the substance (kg), c is the specific heat (J g⁻¹ °C⁻¹) and ΔT is the temperature difference (°C).

Q = ?

m = 100.0 g

c = 4.18 J/g°c

ΔT = (37 - 4) °C = 33 °C

By applying the formula,

Q = 100.0 g x 4.18 J/g °C x 33°C

Q = 13794 J

Hence, needed energy is 13794 J.