Determine the limiting reactant, theoretical yield and percent yield

Silicon, which occurs in nature as SiO2, is the material from which most computer chips are made. If SiO2 is heated until it melts into a liquid, it reacts with solid carbon to form liquid silicon and carbon monoxide gas. In an industrial preparation of silicon, 63.8 kg of SiO2 reacted with 25.8 kg of carbon to produce 22.4 kg of silicon.

Determine the limiting reactant, theoretical yield and percent yield...

so step no.one is to write a balanced equation
sio2 + 2c ---> si + 2co

1 mole sio2 + 2mole c -------------> 1 mole si +2 mole co

now sio2
mass 63.8
mr 28+32 = 60
no.of mole of sio2 = 63.8/60 = 1.0633


now carbon
mass 25.8
Ar 12
No.of mole of C = 25.8/12 = 2.15
so now 1 mole sio2 ----> 2 mole c
so 1.o63 mole _---------> 2.126 ( cross multiply )

and sio2 was 1.o7 and C 2.15 so now sio2 is the limiting reagent !!

sio2 no. of moles = 63.8/60 as it is in decimal so leave it in fraction

sio2---->si
1 mole--------1 mole
63.8/60-------63.8/60


NOW theoretical yield = 63.8/60 X 28 = 29.8

so percent yield = 22.4/29.8 X 100 = 75.2 %

:) :)