please please help with my chemistry review packet?

Question

PLEASE HELP WITH MY CHEM PACKET PLZ
1. Sulfur and oxygen can react to form both sulfur dioxide and sulfur trioxide. In sulfur dioxide, there are 32.06 g of sulfur and 32.00 g of oxygen. In sulfur trioxide, 32.06 g of sulfur are combined with 48.00 g of oxygen
a. what is the ratio of the weights of oxygen that combine with 32.06 g of sulfur?
b. how do these data illustrate the law of multiple proportions?

2. Describe what part of dalton's atomic theory each chemical statement relates to.
a. H2 + Cl2 -> 2HCl
b. There are 3.01 x 10^23 atoms in 20.04 g of calcium
c. Lead does not change to chromium when it forms lead hydroxide

3. Noble gas consists of three isotopes of masses 19.99 amu, 20.99 amu, and 21.99 amu. The relative abundance of these isotopes is 90.92%, 0.257% and 8.82% respectively. what is the average atomic mass of this noble gas? what noble gas is this?

Answer 1

1 a) dioxide: 32.0 g O/ 32.06 g S
trioxide : 48.0 g O/ 32.06 g S

b) trioxide ratio : dioxide ratio
48.0 g O : 32.0 g O
or 3 : 2

- when two elements form two different compounds, the relative proportion of those elements in one compound divided by the relative proportion in the other compound always gives a ratio of small, whole numbers.


2 a) Atoms cannot be created or destroyed. All atoms present in the reactant molecules appear in the products.

2 b) Hmmm. I think this one is: All matter is composed of tiny particles called atoms. Atoms of the same element are identical.

2 c) Each element has a unique type of atom, which cannot be subdivided nor changed into another type of atom.


3. 19.99 amu x (90.92 %) = 18.175 amu
20.99 amu x (0.257 %) = 0.05394 amu
21.00 amu x (8.82%) = 1.8522 amu

total: 20.08 amu

So go look on your periodic table for an element with the closest atomic mass. Like neon.

Answer 2

I wish I understood it in order to help you but I don't so I hope you can find help here.

http://www.tvgreen.com/apchapt2/documents/apch2practice.htm
http://www.google.com/search?hl=en&q=In+sulfur+trioxide%2C+32.06+g+of+sulfur+are+combined+with+48.00+g+of+oxygen&btnG=Google+Search