1 A redox reaction is one in which . -oxidation and reduction take place together
-reduction takes place, but oxidation does not
-reduction occurs first, then oxidation
-reduction occurs after oxidation

2 A reducing agent ...

-always contains hydrogen
-is oxidized in a redox reaction
-loses oxygen in a redox reaction
-is reduced in a redox reaction

3 Iron(II) oxide can be oxidised to form iron(III) oxide. The (II) and (III) show ...

-the number of iron atoms in the two oxides
-the number of oxygen atoms added in the oxidation
-the oxidation state of the iron in the two oxides
-the nucleon number of the iron in the two oxides

4 When hydrogen is passed over copper(II) oxide, this reaction takes place:
CuO (s) + H2 (g) >Cu (s) + H2O (l)
(A) It is a redox reaction, because
(B) The reducing agent in this reaction is
Ans:

5 This reaction takes place in the blast furnace: Fe2O3 (s) + 3CO ( g) > 2Fe (l) + 3CO2 ( g)
(A) The word equation for the reaction is
(B)It is a redox reaction, because
(C) The reducing agent in this reaction is
Ans:

6 A coil of copper wire (Cu) is placed in a colourless solution of
silver nitrate (AgNO3). The solution changes colour.
(a) What colour does the solution go, and why?
(b) Write an ionic equation for the reaction that takes place.
(c) The copper is said to be oxidized during this reaction. Explain why.

Explain why this is not a redox reaction: CuO (s) + H2SO4 (aq) >CuSO4 (aq) + H2O (I)
Ans:

8 (a) The table shows one period of the Periodic Table. Which one?
(b) Complete the three words. The oxidation state tells you how many electrons an atom has
g , l , or s , in forming a compound.
(c) Why are the oxidation states of the elements in the compounds negative after Group IV?
(d) Why do they decrease after Group IV?
Ans:

9 Using oxidation states, write the formulae of the compounds formed between:
(i) sodium and sulfur
(ii) silicon and chlorine
(iii) aluminium and sulfur
(iv) magnesium and phosphorus

pl help