Answer:
B
C
Explanation: they both are things that we understand but dont know how they are fully made of.
Answer:
The correct answer is option c.
Explanation:
Alkanes with higher molecular mass has higher boiling point.
Thisis because when the molar mass of the alkanes increases the the surface area increases with which van der Waals forces between the molecules of alkane also increase which increases the association of the molecules of with each other which results in increase in boiling point is observed.
The increasing order of the molar mass of the given alkanes;

So out of ethane, pentane and heptane . Heptane has highest molecular mass with higher boiling point value. Where as ethane have the lowest value of boiling point.
Here, we should use combined gas law which can be derived from combined gas law, “PV=nRT”. Rearranging, we can get PV/T=nR. Then we can set the two states in the problem together to get
P1V1/T1 = P2V2/T2
Then just plug in and solve algebraically.
Hope this helps
gdm^-3/gmol^-1
g/g=1 dm^-3/1=dm^3 1/mol^-1=mol^1 1 x dm^-3 x mol^1 mol/dm^3
To convert from g/dm^3 to mol/dm^3 you have to divide g/dm^3 by g/mol or the molecular mass.