# Chemistry

posted by
**anonymous** on
.

Can someone please check my answers for me for the following questions. THANK YOU!

1) An ion with an oxidation number of 3+ can combine with three other ions, if each of these ions has an oxidation number of....3-

2) The correct formula for nickel(II) chloride is...NiCl2

3) A compound composed of lithium and nitrate polyatomic ion is...LiNO3

4) How many forumla units are represented by 3K2SO3...my answer is 3

5) Which of the following is an organice compound?

a. H2SO4

b. C2H2

c. MgO

d. KNO3

I chose...B

You need to rethink 1. If an ion is 3+ and it combines with three other ions, then it will have the formula AX_{3}; therefore, X would need to be something but not -3. (The TOTAL charge of X would be -3 but EACH would not be -3.

2 and 3 are ok.

3. Your answer of 3 would be correct if not for the coefficient of 3 in front of the K2SO3. EACH K2SO3 has 3 formula units but the coefficient multiplies everything by 3; therefore, there are 6 K and 3 SO3 for a total of 9.

5. B is correct.