To a sample of water at 23.4oc in a constant pressure calorimeter of negligible heat capacity is added a 12.1 g piece of aluminium whose temperature is 81.7oc. if the final temperature of water is 24.9 oc, calculate the mass of the water in the calorimeter. ans: 98.6g

-i know that the specific heat of aluminum is 0.900 j/g ‡ ác
- _t al is 24.9ác _ 81.7ác = _56.8ác
- _twater and _tcalorimeter are both 24.9ác _ 23.4ác = 1.5ác.
-the specific heat of water is 4.184 j/g ‡ ác.
but i tried using m=q/s_t. i'm really stuck, can anyone me?

98.6 grams

Explanation:

As we know that,  

        .................(1)

where,

q = heat absorbed or released

= mass of aluminium = 12.1 g

= mass of water = ?

= final temperature =

= temperature of aluminium =

= temperature of water =

= specific heat of aluminium =

= specific heat of water=

Now put all the given values in equation (1), we get

Therefore, the mass of the water in the calorimeter is 98.6 grams

the electrical  conductivity  of asolution  of an electrolyte is measured by determining the resistance of thesolution  between two flat or cylindrical electrodes separated by a fixed distance.