Brass is an alloy containing copper and?
zinc
tin
aluminium
silver
lead
Correct answer is A
Brass is an alloy containing copper and zinc
Which of the following processes NOT lead to a chemical change?
Strirring iron in sulphur (IV) acid
Stirring sodium carbonate in water
Stirring glucose in concentrated sulphur (IV) acid
Mixing sulphur (IV) acid with potassium carbonate
Titrating an acid against base
Correct answer is B
Stirring Na2CO3 in water does not lead to a chemical change
1,160 kJ mol-1
1,180 kJ mol-1
1,560 kJ mol-1
1,600kJ mol-1
1,680 kJ mol-1
Correct answer is E
The heat of combustion of methane is 1680 KJ mol-1
Which of the following is NOT a redox reaction?
2HNO2 + 2HI → 2H2O + 2NO + I2
Zn + H2SO4 → ZnSO4 + H2
Ca(HCO3)2 → CaCO3 + H2O + CO2
4FeO + O2 → 2Fe2O3
2Na + Cl2 → 2NaCl
Correct answer is C
Ca(HCO2) → CaCO3 + H2O + CO2 is not a redox reaction
Which of the following combinations of conditions may increase the rate of a chemical reaction?
Decrease in temperature, increase in concentration of the reactants
Increase in temperature, addition of a catalyst, decrease in the surface area of the reactants
Increase in temperature, increase in concentration, addition of a catalyst and increase in the surface area of the reactants
Decrease in temperature concentration and surface area of the reactants
Additionof a catalyst and in the absence of light
Correct answer is C
Increase in temperature, increase in concentration, increase the rate of chemical reaction