Question

I missed a few days of school due to a sick child. I'm reviewing for an exam and the following questions are giving me trouble as I wasn't there when they were reviewed in class. If possible, I need the step-by-step process. Thanks.

1.) If you put hydrogen peroxide on a cut, you’ll notice that it bubbles. The bubbles are diatomic oxygen which is effectively “sterilizing” the wound. If you had 10 g of H2O2, how many grams of oxygen would you form on the cut.

2.) Alka Seltzer is a solid mixture of sodium bicarbonate and citric acid that when placed in water undergoes this reaction…..fizzing.
3NaHCO3(s) + C6H8O7(s) = 3CO2(g) + 3H2O(l) + Na3C6H5O7(aq)
Who is the limiting reactant if you had 100g each of sodium bicarbonate and citric acid?

Answer 1

a. Pure H2O2?

mass O2=10 (2*16/(2(16+1))=10 (32/34)

b. figure moles of each
moles NaHCO3=100/molmass
moles acid=100/molmass

now, do you have three times the moles of bicarb as do you have of acid? (look at the equation coefficents).
If you have more than three times as much bicarb, then the limiting reactant is the acid.

Answer 2

Ah, this is what it means "below". In the second question I posted (above I guess) I rephrased my question for answer and all work. I'm really confused as to what your provided answer means as I missed these classes. I honestly have no idea what to make of the information you provided me, Sir.

Answer 3

I've tried to help at your other post.

Answer 4

Thank you so much. This is sure to be very helpful!