Question

1. A 74.2-g piece of metal is heated to 89.55 degrees C and dropped into 52.0 g of water at 23.22 degrees C in a calorimeter with the heat capacity of 41.0 ^J/_C . The final temperature of the system is 27.60 degrees C.

a) Assuming that the metal does not react with water and C_s(H2O) = 4.18 ^J/_g*C , calculate the specific heat capacity of the metal in ^J/_g*C

b) Most metals have the same molar heat capacity of about 3R (where R = 8.31 ^J/mol_*C ). Calculate the molar mass of the metal used in this experiment.

c) What is the likely identity of the metal if it is in group 10 of the Periodic Table?

Thank you!

Answer 1

1)

a) mass of metal = 74.2 g

mass of water = 52.0 g

temperature of metal = 89.55 oC

heat loss by metal = heat gain by water

m Cp dT = m Cp dT) water + Cp dT

74.2 x Cp x (89.55 - 27.60) = 52 x 4.18 x (27.60 - 23.22) + 41 x (27.60 - 23.22)

specific heat of Cp of metal = 0.246 J /g oC

b)

molar mass of metal = 3 x 8.31 / 0.246

                                 = 101.3 g/mol

c)

identity of metal = Pd (palladium)