A synthesis using a limiting reagent? HELP.?

Question

There are two questions. I think I may have the answer...yet I'm not complete on them. And It is due this morning..and the prof. wasn't at office hours yesterday.

(1) concentrated phosphoric acid is 85.0 % H3PO4 by mass. The density of the solution is 1.70 g/mL. What volume is required to provide 2.50 grams of H3PO4?
_________en.

(2) What is the maximum yeild of isopentylacetate that can be prepared from 3.58 g of isopentanol and 4.75 g of acetic acid?
___________________g.

I would appreciate the help very much.

Answer 1

(1) If you need 2.50 grams of acid, then the grams of 85% solution is

2.50 g / 0.85 = 2.941 grams of solution.

If the density is 1.70 g/mL, then the volume needed is

2.941 grams / 1.70 g/mL = 1.73 mL of the solution.

(2) From the balanced equation:

(CH3)2CHCH2CH2OH + CH3COOH --> (CH3)2CHCH2CH2OOCCH3

One mole plus one mole yields one mole

3.58 g / 88.17 g/mole = 0.0406 moles of alcohol
4.75 g / 60.05 g/mole = 0.0791 moles of acid

At most 0.0406 moles of ester will be formed

0.0406 moles * 130.19 g/mole = 5.286 grams

Trivia: Isopentylacetate smells like bananas.