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 
The way you calculate the empirical formula is to firstly assume 100g. To find each elements moles you take each elements percentage listed, times it by one mole and divide it by its atomic mass. (ex: moles of K =55.3g x 1 mole/39.1g, therefore there is 1.41432225 moles of Potassium) Once you’ve completed this for every element you list each elements symbol beside it’s number of moles and divide by the smallest number because it can only go into its self once. After you’ve done this, you’ve found your empirical formula, which is the simplest whole number ratio of atoms in a compound. I’ve added an example of a empirical question I completed last semester :)
You must first calculate the total weight of 1 mole of the substance. You do this by finding the molar weights on the periodic table of each of the elements in the compound:

So now we take the amount of each element that is given in the compound and divide it by the total mass of the compound:
Carbon: 96.08g

Carbon = 49.48%
Nitrogen: 56.028g

Nitrogen = 28.85%
Oxygen: 31.998g

Oxygen = 16.48%
Answer:
Molecules make scents. Aromatic ones (That is, containing rings of carbon atoms with delocalised electrons). Some unpleasant smells are due to hydrogen and sulphur groups.
Explanation:
I think C. Mutualism.
Hope this helps :)