Given the volume of water and its density, we can find the mass.

Given the volume of water and its density, we can find the mass.

$$\text{Mass of water} = \text{Volume of water} \times \text{Density of water}$$ $$m = 450 \text{ cm}^3 \times 1 \text{ g/cm}^3 = 450 \text{ g}$$

Convert the mass from grams to kilograms:

$$m = 450 \text{ g} = 0.450 \text{ kg}$$

$$\Delta T = \text{Final temperature} - \text{Initial temperature}$$ $$\Delta T = 46.5^\circ \text{C} - 25^\circ \text{C} = 21.5^\circ \text{C}$$

Since a change of $1^\circ \text{C}$ is equivalent to a change of $1 \text{ K}$,

$$\Delta T = 21.5 \text{ K}$$

Given specific heat capacity of water $c = 4.2 \text{ kJ/kg K}$.

$$Q = m \times c \times \Delta T$$ $$Q = 0.450 \text{ kg} \times 4.2 \text{ kJ/kg K} \times 21.5 \text{ K}$$ $$Q = 19.35 \text{ kJ} \times 21.5$$ $$Q = 407.025 \text{ kJ}$$

The heat evolved during the experiment is $\text{407.025 kJ}$.