31P3

Question: Atomic number is the________ in the nucleus of an atom.

Answer: protons

Question: How many moles of Mg3P2(s) can be produced from the reaction of 0.570 mol Mg(s) with 9.17E-2 mol P4(s)?

6 Mg(s) + P4(s) → 2 Mg3P2(s)

Answer: 0.183 mol

Question: A compound is found to contain 74.76% by mass F and 25.24% by mass S, with a molecular weight of 254.14. What is the molecular formula for this compound?

Answer: S2F10

Question: Which of the following is the smallest mass

Answer: 2.87E-5 g

Question: Write a balanced chemical equation for the combustion of copper to yield copper(I) oxide.

Answer: 4 Cu(s) + O2(g) —> 2 Cu2O(s)

Question: Which of the following are a pair of isotopes?

Answer: same element- diff number of neutrons

Question: Which of the following compounds are named correctly?

1. CrCl3, chromium(II) chloride

2. 2. PCl3, phosphorous chloride

3. 3. NF3, nitrogen trifluoride

4. Answer: 3 only

5. Question: Identify the ions present in KClO4

6. Answer: K+ and ClO4-

7. Question: How many protons, neutrons and electrons are present in one ion of 31P3-?

8. Answer: protons = 15, neutrons = 16, electrons = 18

9. Question:

10. Answer: E