Assuming the mass of the ice in the beaker was 2000 g (2 kg), calculate the amount of heat that must have been added to convert the ice to water (assume that the entire 2000 g was ice at the start of melting, and the entire 2000 g was water at the end of the melting). assume that the change took place entirely at 0 °c. the heat of fusion (dhfus) for h2o is 6.12 kj/mol.