a level chemistry

This question is about a toxic chloroalkane, X, that has a boiling point of 40 °C.
A student carried out an experiment to determine the Mr of X by injecting a
sample of X from a hypodermic syringe into a gas syringe in an oven at 97 °C
and 100 kPa. The student’s results are set out in Table 1 and Table 2.
Table 1
Mass of hypodermic syringe filled with X before
injection / g 10.340
Mass of hypodermic syringe with left over X after
injection / g 10.070
Mass of X injected / g
Table 2
Volume reading on gas syringe before injection of X /
cm3
0.0
Volume of X in gas syringe after injection of X / cm3 105.0
Volume of X / cm3
(a) Complete Table 1 and Table 2 by calculating the mass and volume of X.
(1)
(b) X is known to be one of the following chloroalkanes: CCl4 CHCl3 CH2Cl2
or CH3Cl
Justify this statement by calculating a value for the Mr of X and use your
answer to suggest the most likely identity of X from this list.
Give your answer for the Mr of X to an appropriate precision.
(The gas constant R = 8.31 J K−1 mol−1
Identity of X
(If you have been unable to calculate a value for Mr, you may assume that
the Mr value is 52. This is not the correct value). i found the mr to be 79.1 how do which chloroalkane is it.

What have you tried so far?

i don't know what choloralkane is as i haven't learn it ( i only started year 12 know) i just hope it not something i can figure out.