A and 3
B and 6
C and 5
D and 1
E and 2
F and 4
First of all write a balanced equation.
4Na + O2 -> 2Na2O
You are starting with a mass of sodium. You need to use sodium’s molar mass. Take this quantity times mole to mole ratio between sodium and sodium oxide to get moles of sodium oxide produced.
.141 moles of sodium oxide produced
the correct answer should be a
Answer: The formula for this hydrate is 
Explanation:
Decomposition of hydrated copper sulphate is given by:
Molar mass of 
= 160 g/mol
According to stoichiometry:
(160+18x) g of 
decomposes to give 160 g of anhydrous
Thus 42.75 g of decomposes to give=
g of anhydrous
Thus the formula for this hydrate is
