How much energy is needed to convert 90g of water (ice) at -85 degrees C to water (liquid) at 48 degree C?

Answer 1

Two formulas will get this for you.
For changes in temperature WITHIN a phase use q = mass x specific heat x (Tfinal-Tinitial).
example:for liquid water from zero C to 100 C. it will be q = mass H2O x specific heat H2O x (100-0)

For changes at the phase change use
q = mass x heat fusion at the melting point.
q = mass x heat vaporization at the boiling point.

Then add all of the qs together for total Q.
Post your work if you get stuck.