How much energy will it take to melt 100 grams of ice at 0◦C?

The answer is: ##33.4kJ##
To answer to this question it is sufficient to use this equation:
##Q=Lm##
where
##Q## is the amount of heat needed to melt the ice (the request of the problem;
##L## or ##L_(ice)## is the of melt for ice, that is:
##L_(ice)=3.34 · 10^5 J/(kg)##;
##m## is the mass of ice that is to melt, that is:
##m=100g=0.1kg##.
So:
##Q=3.34 · 10^5 J/(kg).0,1kg=33,400J=33.4kJ##