chemistry
posted by anita on .
When 0.320 moles of NH4Cl is dissolved in 1.00 L of water, the temperature drops by 13.7 degrees C. What is the heat of solution of ammonium chloride? The solution has a density of 1.0012 g/mL and a specific heat of 0.9818 cal/g degrees C.
How do you find the mass of water to use in the equation:
q = mass water x specific heat water x delta T.

mass water = volume water x density water. Watch the units.

why do you need to use the mass of water in the q= equation, if you're trying to find the heat of solution of ammonium chloride?

The water is what changed temperature by 13.7 degrees C.
Isn't your formula
q = mass water x specific heat water x delta T? The water temperature is the vehicle by which you determine what NH4Cl does when placed in solution and by how much. 
how do u find density of the water?