Steel. Practical work 3
Answers are for parents and teachers.
1
In 2FeO + Si → 2Fe + SiO₂ name the oxidising and the reducing agent.
FeO (Fe²⁺) is the oxidiser; Si is the reducer.
2
How many grams of P₂O₅ form when 62 g of phosphorus is oxidised by 5FeO + 2P → 5Fe + P₂O₅? (A(P) = 31, M(P₂O₅) = 142)
142
3
Write equations for three different ways of preparing MgCl₂.
Mg + 2HCl → MgCl₂ + H₂↑; MgO + 2HCl → MgCl₂ + H₂O; MgCO₃ + 2HCl → MgCl₂ + H₂O + CO₂↑ (or Mg(OH)₂ + 2HCl → MgCl₂ + 2H₂O).
4
Three test tubes hold NaCl, FeCl₃ and Na₂CO₃ solutions. How would you identify them?
FeCl₃ by its colour; adding acid releases CO₂ from Na₂CO₃; the remaining one is NaCl (white AgCl with AgNO₃).
5
Name an environmental problem of steel production and a way to reduce it.
Dust, gases and slag; filters, recycling of waste, making sponge iron with hydrogen or natural gas instead of coke.