Question

How many moles of CF₄ can be produced when 7.00 mol C react with 4.00 mol F₂?

mol CF₄

How many moles of each reactant are left over? Note that at least one must disappear.

mol C remain

mol F₂ remain

Answer 1

reaction taking place is
C + 2F2 --> CF4
according to reation
2 mole of F2 react with 1 mol of C
1 mole of F2 react with 1/2 mol of C
4 mole of F2 react with (1/2)*4 mol of C
4 mole of F2 react with 2 mol of C

but we have 7 mol of C
so, C is in excess
number of mol of C remains = (7 - 2) mol
= 5 mol
number of mol of F2 remains = 0

again according to reaction
2 mol of F2 give 1 mole of CF4
1 mol of F2 give 1/2 mole of CF4
4 mol of F2 give (1/2)*4 mole of CF4
4 mol of F2 give 2 mole of CF4
number of mole of CF4 formed = 2 mole