[k3107q]

Hi everyone , i'm newbie and nice to meet you guy ,I have some question still confusing ,please helpme out .Thanks

Thermite is a reaction that was once used to weld railroads together as shown below. A 48.0 g sample of Al(s) was reacted with 99.0 g of Fe2O3 according to the equation below. What could be the theoretical yield of Fe(s) in grams?

2 Al(s) + Fe2O3(s) ---> Al2O3(s) + 2 Fe(s)

a)69.2 g
b)99.3 g
c)48.0 g
d)175 g
e)52.5 g

=> This question ,I think a OR b but not sure

2)A way of generating dry O2 in the lab is to heat potassium chlorate. If you determined that 25 grams of O2 are needed, how much potassium chlorate do you need to start with if there is only a 60% yield?

2KClO4 --->(HEAT)--> 2KCl +4O2

a)64 grams
b)25 grams
c)17 grams
d)106 grams
e)96 grams

[Borek]

http://www.chembuddy.com/?left=balancing-stoichiometry&right=stoichiometric-calculations