What mass of oxygen is needed to react with 8.5 grams of hydrogen sulfide? The products of this reaction are sulfur dioxide and water.

(a)  

What mass of potassium oxide is formed when 7.8 g of potassium is burned in oxygen?

(a)  

Railway lines are welded together by the Thermite reaction, which produces molten iron.  What mass of iron is formed from 1 kg of iron oxide?

                                Fe₂O₃ + Al  --> Fe  +  Al₂O₃

(a)  

What mass of oxygen is required to oxidise 10 grams of ammonia to NO?

(a)  

What mass of aluminium oxide is produced when 135 g of aluminium is burned in oxygen?

(a)  

What mass of iodine is produced when 7.1 grams of chlorine reacts with excess potassium iodide?

(a)  

What mass of hydrogen is needed to react with 32 grams of copper (ii) oxide?

(a)  

What mass of oxygen is formed when 735 grams of KClO₃ decomposes to produce oxygen and a salt. Give your answer to 3 s.f.

(a)  

What volume of hydrogen is produced when 195 mg of potassium is added to water? Give your answer in cm³.

(a)  

How much calcium oxide is produced by heating 50 g of calcium carbonate?

                                CaCO₃  --> CaO  +  CO₂

(a)  

What mass of magnesium oxide is formed when 6 grams of magnesium reacts with oxygen?

(a)  

What volume in m³ of carbon dioxide is produced when 5.6 grams of butene combusts?

(a)  

The pollutant sulfur dioxide can removed from the air by reaction with calcium carbonate in the presence of oxygen.  How many tonnes of calcium carbonate is needed to remove 1 tonne of sulfur dioxide? Give your answer to 3 s.f.

                                2CaCO₃  +  2SO₂  +  O₂  -->  2CaSO₄  +  2CO₂

(a)  

5.00 g of hydrated sodium sulfate crystals (Na₂SO₄.nH₂O) gave 2.20 g of anhydrous sodium sulfate on heating to constant mass. 

Work out the relative molecular mass (M_r) of the hydrated sodium sulfate:

                                Na₂SO₄.nH₂O  --> Na₂SO₄  +  n H2O

(a)