Ionic molecules have higher boiling point than covalent molecules.
So that leaves Na2SO4 and NaCl.
The ionic molecule with higher charge will have higher boiling point.
Na2SO4 have ions with charge +-2.
NaCl have ions with charge +-1.
So the answer is C.
D! because when you record something you will probably analyze the results and those are two big KEY components of an Experiment! <span />
Answer:
56°
Explanation:
First calculate 

The interplanar spacing can be calculated from:

The diffraction angle is determined from:

Solve for 

The diffraction angle is:

Answer:
Only the number of neutrons change.
<span>Van der waal or ideal eqn is given by PV = NRT; P = NRT/ V.
Where N = 1.335 is the number of moles. T = 272K is temperature. V = 4.920L is the volume. And R = 0.08205L. Substiting the values into the eqn; we have,
P = (1.331* 0.08205 * 272)/ 4.920 = 29.7047/ 4.920 = 6.03atm.</span>