Question

a 36.9g sample of metal is heated to 100.0 degrees celcius, and then added to a calorimeter containing 141.5g of water at 23.1 degrees celcius. the temperature of the water rises to a maxiumum of 25.2 degrees celcius before cooling back down.

a) did the water absorb heat or did it release heat?

b) how many joules of heat was exchanged between the water and the metal?

c) what is the identity of the metal?

Answer 1

mass of metal = 36.9 g

temperature of metal = 100 oC

mass of water = 141.5 g

temperature = 23.1 oC

a)

here water absorb heat

b)

heat Q = m Cp dT

            = 141.5 x 4.184 x (25.2 - 23.1 )

            = 1243.3 J

heat exchanged = 1243 J

c)

heat loss by metal = heat gain by water

36.9 x Cp x (100 - 25.2) = 1243.3

Cp = 0.450

specific heat = 0.450 J / g oC

identity of metal = iron