Water is H2O but I'm not sure about solids.
Hey there mate ;), Im Benjemin and lets solve your question.
★ (Alkanes) : forms single bonds between carbon atoms.
The first four elements are gases and others are liquid in state.
★(Alkenes) : forms double bonds between carbon atoms.
The first three alkenes are gases and rest are liquid.
★ (Alkynes) : forms triple bonds between carbon atoms.
First three are gases and the last one is liquid.
According to boiling point :
The larger structure of the hydrocarbons, the higher the boiling points they have.
In the 3 tables, we can see that the boiling point increases.
Answer:
0.808 M
Explanation:
Using Raoult's Law

where:
= vapor pressure of sea water( solution) = 23.09 mmHg
= vapor pressure of pure water (solute) = 23.76 mmHg
= mole fraction of water
∴






------ equation (1)
------ equation (2)
where;
number of moles of sea water
number of moles of pure water
equating above equation 1 and 2; we have :



NOW, Molarity = 



As we assume that the sea water contains only NaCl, if NaCl dissociates to Na⁺ and Cl⁻; we have 
<span>There are only three stereoisomers of 1,2-dimethylcyclopentane. As there are only two chiral carbons, so the maximum number of stereoisomers is 4, but two are the same meso-compound which means that there are only 3.</span>