Answer:
a.

b. fluorine
c. 2.45 moles
d. 0.52 moles
Step-by-step explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
a) The balanced chemical equation is:

Given : moles of chlorine = 1.75
moles of fluorine = 3.68
By Stoichiometry of the reaction:
3 moles of fluorine reacts with = 1 mole of chlorine
So, 3.68 moles of fluorine reacts with =
of chlorine
b) Thus fluorine is the limiting reagent as it limits the formation of product.
Chlorine is the excess reagent and (1.75-1.23) = 0.52 moles of chlorine are left over.
As 3 moles of fluorine give = 2 moles of chlorine trifluoride.
3.68 moles of fluorine will give =
moles of chlorine trifluoride.
c. Thus 2.45 moles of chlorine trifluoride
are produced.
d. 0.52 moles of chlorine are left over.