Coal falls under Graphite
Answer:
The mole fraction of NaOH in an aqueous solution that contain 22.9% NaOH by mass=0.882
Explanation:
We are given that
Aqueous solution that contains 22.9% NaOH by mass means
22.9 g NaOH in 100 g solution.
Mass of NaOH(WB)=22.9 g
Mass of water =100-22.9=77.1
Na=23
O=16
H=1.01
Molar mass of NaOH(MB)=23+16+1.01=40.01
Number of moles =
Using the formula
Number of moles of NaOH

Molar mass of water=16+2(1.01)=18.02g
Number of moles of water

Now, mole fraction of NaOH
=

=0.882
Hence, the mole fraction of NaOH in an aqueous solution that contain 22.9% NaOH by mass=0.882
statement c would be correct I think.
Answer:
A) SiO2 is the limiting reactant
B) Theoretical yield= 72333.3g
C) % yield =91.5%
Explanation:
SiO2(s) + 2C(s) --------------> Si(s) + 2CO(g)
n(SiO2)= 155000/60 = 2583.33 mols
n(C)= 79000/12= 3291.66 mols
a)SiO2 is the limiting reactant
According to the balanced reaction equation,
60g of SiO2 produced 28g of SiO2
155000g of SiO2 will produce 155000×28/60= 72333.3g
Therefore theoretical yield of Si= 72333.3g
% yield= 66200/72333.3×100/1 =91.5%