Question

If I need to find q, when q=m x s x delta t, of the addition of 4.012 g of solid NH4Cl to 100 mL of H2O, would my mass be just the 4.012 since NH4 and Cl dissociate? Or would it be 104.012 since I would have to include the mass of the water? Could you also include the equations for the answer to help me understand how you got the answer? Thank you!

Answer 1

The equation for calculating heat is ,

q=m x s x delta t

here m is total mass, s is specific heat and delta T is change in temperature.

Total mass of solution = mass of NH4Cl + mass of water

we know density of water is 1 g/ml

so, total mass = 4.012 g + 100 ml x 1 g/ml = 104.012 g

Here we need to take assumption that, specific heat of solution is equal to specific heat of water.

so, s = 4.18 J/g ^oC

so, heat q = 104.12 g x 4.18 J/g ^oC x delta t

Here subtitiute your delta t values in the above equation