I need some help 3KOH + FeCl3 → Fe(OH)3 + 3KCl
How many moles of FeCl3 are needed to completely react with 3.0 g of KOH?

0.0178

Explanation:

because you can work out the amount of moles in KOH using moles = mass/mr.

The mr of the KOH is 39.1+16+1=56.1 so you do

which equals to 0.053475 so u 3SF which is 0.0535moles

than u uses the molar ratio which is 3 to 1

so 0.0535÷3=0.0178 which is the moles of FeCl3.

hope this make sense:)

1.solid

2.carbon dioxide

3.helium