To calculate the amount of heat required to melt 20 grams of ice at 0C and convert it to liquid water at 0C, we will use the formula:q = n Hfwhere q is the heat required, n is the number of moles of the substance, and Hf is the enthalpy of fusion.Step 1: Calculate the number of moles of iceThe molar mass of water H2O is 18.015 g/mol. To find the number of moles n in 20 grams of ice, we will use the formula:n = mass / molar massn = 20 g / 18.015 g/moln 1.11 molesStep 2: Calculate the heat requiredNow that we have the number of moles, we can use the formula q = n Hf to find the heat required to melt the ice:q = 1.11 moles 6.01 kJ/molq 6.67 kJTherefore, approximately 6.67 kJ of heat is required to melt 20 grams of ice at 0C and convert it to liquid water at 0C.