[JOE111111]

1.the equation for the reaction of magnesium and fluorins is :
Mg + F2 -> MgF2

a)how many moles of fluorine molecules react with one mole of magnesium atoms?
b)what is the relative frmula mass of MgF2?(Ar values: Mg = 24, F =19)



2. the relative atomic mass of oxygen is 16, and that of magnesium is 24. how many times heavier is a magnesium atmo than an oxygen atom?


3. ammonium nitrate (NH4NO3) is used as a fertiliser. what is the percentage mass of nitrogen in it? (ar values = H = 1, N = 14 , O = 16)



4. 22.5% of the mass of a sample of phosphorus chloride is phosphorus. what is the formula oh phosphorus chrloride? (ar values : P=31, Cl = 35.5)




5. hydrogen peroxide, H2O2, decomposes to form water nd oxygen gas. wrtie a balanced equation for this reaction.


6. calcium reats with oxygen like this :

2Ca + o2 -> 2CaO


what mass of oxygen qill react exactly with 60g of calcium?
(Ar values : O = 16 , Ca = 40)





7.a reaction prudeces a product which has a relative formula mass of 80. the total of the relative forumla masses of all the products is 120. what is the pecentage atom economy of thie reaction ?

8. a reaction that could produce 200g of product produces only 140 g what is the percentage yield?

9.if the percentage yiel for a reaction is 100%, 60g of reactant A would make 80g of product C How much of reactant A is needed to make 80 g of product c if the percentage yield of the reaction is only 75%?