How much heat is absorbed to change 36.0 grams of water from a solid to a liquid at 0 degrees celsius (δhfusion = 6.02 kj/mol)?

1 mol of H2O = 18g

so 36 g= 2 mol

for one mole we require 6.02 kilo joule so for 2 mol 12.04 kJ is required

Explanation:

Hope that vlears your doubt

altitude, density, pressure

air gets less dense the higher the altitude and also the air pressure is less as altitude rises.

i'm assuming that the correct answer is indeed the first one/ "a"..