Posted by **jezzaD.** on Wednesday, January 23, 2013 at 10:06am.

1. Identify the percent composition of sodium carbonate.

2. Determine the percent composition of calcium in calcium carbonate.

Pls. help me... my prob is that there is something in the solution that bothers me.. pls.kindly show me how to do.. i'll thank u later... :)

- Chemistry-II (Percent Composition) -
**Devron**, Wednesday, January 23, 2013 at 12:54pm
In your first question, 1 mole of sodium carbonate=2 moles of sodium=1 mole of carbon =3 moles oxygen. Take the moles for each of the components in sodium carbonate and multiply them by their respective molecular weights e.g. 3 moles of oxygen* 15.999g/mole to calculate the weight of oxygen in sodium carbonate. Since the molecular weight of sodium carbonate is 105.9784 g/mol, the weight that you calculate for oxygen divided by the the molecular weight of sodium carbonate multiplied by 100 will give you the percent composition of oxygen in sodium carbonate ([weight of oxygen/105.9784] *100); perform these steps for each of the additional components in sodium carbonate.

The answer to the second question is the same, but you only need to do the steps mentioned above with Ca. 1 mole of Ca= 1 mole of calcium carbonate. Take the molecular weight of Ca and divide it by the molecular weight of calcium carbonate, which is 100.0869 g/mol. Remember to multiply that number by 100 to get percent.

- To JezzaD---Chemistry-II (Percent Composition) -
**DrBob222**, Wednesday, January 23, 2013 at 3:43pm
Why not tell us what the problem is and let us answer that specific question instead of working on problems that may or may not be troubling you.

## Answer This Question

## Related Questions

- Chemistry - How do you determine the percent composition by mass of a 100 g ...
- science - Sodium hydrogen carbonate NaHCO3, also called baking soda, is an ...
- Chemistry - A solution of 100.00mL of 0.2000mol/L sodium carbonate and 200.00mL ...
- chemistry - 1.to calculate the percent by massof an element in a known compound...
- Chemistry - Please help, I have been trying to figure this out for some time: ...
- Chemistry 11 - Find the percent composition of a compound containing sodium and ...
- Chemistry Lab - We did a lab where we reacted antacid with HCL and measured the ...
- chemistry - Write the correct equation for the formation of a white precipitate ...
- CHEMISTRY - A 2.800-g mineral sample was analyzed for its calcium carbonate, ...
- chemistry - What is the percent mass of calcium in a calcium supplement if 1.06 ...

More Related Questions