To calculate the specific heat capacity c of water, we can use the formula:q = mcTwhere q is the heat absorbed 400 J , m is the mass of water, c is the specific heat capacity, and T is the change in temperature 20C .We need to know the mass of water to calculate the specific heat capacity. Assuming we have 100 grams of water, we can rearrange the formula to solve for c:c = q / mT c = 400 J / 100 g 20C c = 400 J / 2000 gCc = 0.2 J/gCSo, the specific heat capacity of water in this case is 0.2 J/gC. However, it's important to note that the specific heat capacity of water is generally known to be 4.18 J/gC. The calculated value may be different due to experimental errors or inaccuracies in the given data.