# Ch3 notes part 1 answers - Answers to example questions for...

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

Answers to example questions for CH3: Moles, % composition, balancing equations NOTE: Wherever you see an it indicates where you could stop the calculation for an alternative question, and also shows what the answer would be to that alternative question. Calculate the number of moles of Mg atoms, and, number of individual atoms in 4.5 μ g of Mg. 4.5 x 10 -6 g Mg*(1mol Mg / 24.31g Mg)*(6.022 x 10 23 atoms Mg /1 mole Mg) moles of Mg (=1.85 x 10 -7 moles) = 1.11 x 10 17 atoms Mg Calculate the number of moles of molecules and number of individual molecules in 74.6 g of propane, formula C 3 H 8 First, calculate the MW of C 3 H 8 : = (3x12.01g/mol) + (8x1.008g/mol) = 44.094g/mol 74.6g C 3 H 8 * (1mole C 3 H 8 / 44.094g C 3 H 8 )*(6.022 x 10 23 molecules C 3 H 8 /1 mole C 3 H 8 ) moles of C 3 H 8 (1.692 moles) = 1.02 x 10 24 molecules C 3 H 8 Calculate the number of O atoms in 26.5 g of Lithium Carbonate. Lithium Carbonate is Li 2 CO 3 . Calculate FW :

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

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 04/27/2010 for the course CH 301 taught by Professor Fakhreddine/lyon during the Spring '07 term at University of Texas.

### Page1 / 2

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

View Full Document
Ask a homework question - tutors are online