# Homework Help: Chem help!

1. Feb 10, 2013

### ScienceGeek24

1. The problem statement, all variables and given/known data
1.It takes 15 drops of solution A to react completely with 29 drops of solution B? Which equation below represents this reaction in the smallest whole number ratio? Assume that solution A and solution B have the same molarity.

Remember that there is always a slight amount of experimental error in any measurement.

a)A + 2B
b)2A + B
c)A + B
d)14 A + 7B
e)7A + 14B

2.It takes 25 drops of solution A to react completely with 17 drops of solution B? Which equation below represents this reaction in the smallest whole number ratio? Assume that solution A and solution B have the same molarity.

Remember that there is always a slight amount of experimental error in any measurement.

a)A + 2B
b)2A + 3B
c)24A + 17B
d)2A + B
e)17A + 24B
f)3A + 2B

3.After drying and cooling your crucible, you determine that it has a mass of 20.633 grams. You place a sample of iron in the crucible. The overall mass of the crucible and iron is 27.396 grams. You burn the iron sample in the crucible. Assuming that the combustion of iron metal results in the formation of FeO, what is the combined mass of the crucible and the combustion product in grams?

4.After drying and cooling your crucible, you determine that it has a mass of 22.385 grams. You place a sample of iron in the crucible. The overall mass of the crucible and iron is 26.932 grams. You burn the iron sample in the crucible. Assuming that the combustion of iron metal results in the formation of FeO, what is the combined mass of the crucible and the combustion product in grams?

2. Relevant equations

Stoichiometry?

3. The attempt at a solution

I'm pretty lost with these problems, i do not know how to reason with them.

2. Feb 10, 2013

### Simon Bridge

Well ... how many hydrogens do you need for each oxygen to get water?
If I had oxygen and hydrogen in solution (with something, somehow), at the same molar concentrations, how many drops of hydrogen solution do I need for each drop of oxygen?
How would you write down the equation for that chemical reaction?

This is the lynchpin - what does it mean?