allright, see u have taken the whole mass not the mass of ice which is actually bieng melted, so its not 16.3
u need the mass taken for the ice to melt completely, ie. initial mass of ice melted is 16.3, final mass of ice melted is 2.1... so to get the actuall mass tht was melted u have to subtract
i.e 16.3-2.1=14.2g
then use the formula P x t= mlf
40 x 120 = 14.2 x m (we need to find m)
then sunsitute the equation to : (40 x 120) / 14.2
u get 338j/g which will be ure "M",
do check the mark scheme if its correct....