Practice Problems Week 6

1. How many atoms of aluminum are in 6.75 moles of Al?

2. How many moles are in grams of iodine atoms?

3. How many moles are in grams of iodine molecules?

4. What is the mass, in grams, of one mole of silver?

5. What is the mass, in grams, of one atom of silver?

6. How many atoms of lithium are in 25.0g of lithium?

7. How many grams of gold are in atoms of gold?

8. How many molecules of N₂O₃ are in 5.55 picograms of N₂O₃ ?

9. How many nitrogen atoms are in 1.75 grams of Al(NO₃)₃ ?

10. How many grams of Al(NO₃)₃ are required to produce atoms of oxygen?

11. For each of the following, (a) write a balanced chemical equation; (b) indicate the type of reaction (combination, decomposition, single replacement (displacement), or double replacement (ion exchange)?

(i) Ammonium phosphate + nickel(II) nitrate -> nickel(II) phosphate + Ammonium nitrate

(a)

(b) Double displacement (replacement, partner exchange, ion exchange are synonyms)

(ii) Aluminum + sulfuric acid (hydrogen sulfate) ->

(a) ( (g) and up arrow both indicate gas evolved)

(b) Single replacement

(iii) Aluminum + bromine ->

(a)

(b) Combination

(iv) Potassium nitrate -> potassium nitrite + oxygen

(a)

(b) Decomposition