Workshop 3 answer

Workshop 3 answer - NAMES: _ WORKSHOP 3 (20 points)...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
NAMES: ____________________________________________________________ WORKSHOP 3 (20 points) Stoichiometry Spring 2011 1. (4 pts) (a) How many molecules would be found in a 36.0 gram sample of water? 1.20 x10 24 molecules (b) How many atoms would be found in a 36.0 gram sample of water? 3.60x10 24 atoms Since you need to have your answer in atoms, and there are three atoms (two hydrogen and one oxygen) in one molecule of H 2 O, the answer would be three times as great as the answer to example (a). 2. (5pts) A compound is 75.46% carbon, 4.43% hydrogen, and 20.10% oxygen by mass. It has a molecular weight of 318.31 g/mol. What is the molecular formula for this compound? Moles C= 75.46g/ 12 g/mol= 6.288 moles Moles H= 4.43g/ 1.01g/mol= 4.386 moles Moles O= 20.10g/ 16.0g/mol= 1.256 moles smallest number of moles 6.288/ 1.256= 5 * 2= 10 4.386/ 1.256= 3.492 = 3.5 * 2 =7 1.256/1.256= 1 *2 = 2 Empirical formula C 10 H 7 O 2 has MM= 159.17 g/mol Molecular 318.31g/mol / 159.17 g/mol= 1.99= 2 Molecular formula
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/21/2011 for the course CHEM 102 taught by Professor Peterpastos during the Spring '08 term at CUNY Hunter.

Page1 / 2

Workshop 3 answer - NAMES: _ WORKSHOP 3 (20 points)...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online