A mass of 0.1 kg of helium fills a 0.2 m3 rigid tank at 350 kPa. The vessel is heated until the pressure is 700 kPa. Calculate the a) the temperature change of helium [deg. C], and b) the total amount of heat required for this process [kJ].

Explanation:

(a)   First, we will calculate the number of moles as follows.

       No. of moles =

Molar mass of helium is 4 g/mol and mass is given as 0.1 kg or 100 g (as 1 kg = 1000 g).

Putting the given values into the above formula as follows.

       No. of moles =

                             =  

                             = 25 mol

According to the ideal gas equation,

                           PV = nRT

or,      

          = 336.17 K

Hence, temperature change will be 336.17 K.

(b)   The total amount of heat required for this process will be calculated as follows.

                   q =

                      =

                      = 174573.081 J/K

or,                  = 174.57 kJ/K        (as 1 kJ = 1000 J)

Therefore, the amount of total heat required is 174.57 kJ/K.

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.