PDA

View Full Version : Chemical composition


yeroc6
Feb 16, 2009, 03:10 PM
I need help I don't understand this! :confused:

A sample of sodium carbonate (Na2CO3) weighs 15.0g. Calculate the following Quantities with work shown.

A. moles of NaCO3
B. number of Na2CO3 formula units
C. number of Na+ ions
D. moles of CO3 2- ions

rwinterton
Feb 16, 2009, 09:25 PM
1. Start by calculating the molecular weight of Na2CO3. You have 15 grams, you can calculate the number of moles from the molecular weight and the 15 grams.

2. Formula Units are the same as moles in this case.

3. You can look at the molecular formula to tell how many Na+ ions there are *per mole*

4. Same as #3