Complete Question
A sample of aluminum, which has a specific heat capacity of 0.897 JB loc ! is put into a calorimeter (see sketch at right) that contains 200.0 g of water. The aluminum sample starts off at 85.6 °C and the temperature of the water starts off at 16.0 °C. When the temperature of the water stops changing it's 20.1 °C. The pressure remains constant at 1 atm. Calculate the mass of the aluminum sample.
Answer:

Explanation:
From the question we are told that:
Heat Capacity 
Mass of water 
Initial Temperature of Aluminium 
Initial Temperature of Water 
Final Temperature of Water 
Generally
Heat loss=Heat Gain
Therefore


Two or more different elements
Answer:
V = 15 L
Explanation:
PV = nRT
P = 1.29 atm, T= 355 K mass argon 40g/mol
n = mass/ molecular mass; n = 26.6 g/40 g/mol; n = 0.665 mol
V = (0,665 mol x 0.082 x 355 K) / 1.29 atm = 15 L
Protons,neutrons,electrons