Answer:The formulas of ionic compounds are:
a)
b)
c)
d)
Explanation:
Formulas for the an ionic compounds is determine by:
Criss-cross method, the oxidation state of the ions gets exchanged and they form the subscripts of the other ions. This results in the formation of a neutral compound.
(a) Copper bromide :Given that it contains
ion.

(b) Manganese oxide : Given that it contains
ion.

(c)Mercury iodide :Given that it contains 

(d) Magnesium phosphate :Given that it contains 

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 