Chemistry - Redox Reaction
Exam Duration: 45 Mins Total Questions : 30
Oxidation is defined as
- (a)
lose of electrons
- (b)
gain of electrons
- (c)
gain of protons
- (d)
lose of neutrons
Which one the following statement is correct?
- (a)
Oxidation of a substance is followed by the reduction of another
- (b)
Reduction of a substance is followed by the oxidation of another
- (c)
Oxidation and reduction are complementary reactions.
- (d)
It is not necessary that both oxidation and reduction should take place in the same reaction
Which of the following is not an example of redox reaction?
- (a)
\(CuO+h_2\rightarrow Cu+H_2O\)
- (b)
\(Fe_2O_3+3CO\rightarrow 2Fe+3CO_2\)
- (c)
\(2K+F_2\rightarrow 2KF\)
- (d)
\(BaCl_2+H_2SO_4\rightarrow BaSO_4+2HCl\)
Which one of the following reactions is not a redox reaction?
- (a)
\(Ag^++Cl^-\longrightarrow Ag^+Cl^-\)
- (b)
\(Zn(s)+Cu^{2+}(aq)\longrightarrow Zn^{2+}(aq)+Cu(s)\)
- (c)
\(2Mg(s)+O_2(g)\longrightarrow 2Mgo\)
- (d)
\(FeO+C\longrightarrow Fe+Co\)
Identify disproportionation reaction.
- (a)
\(CH_4+2O_2\longrightarrow CO_2+2H_2O\)
- (b)
\(CH_4+4Cl_2\longrightarrow CCl_4+4HCl\)
- (c)
\(2F_2+2OH^-\longrightarrow 2F^-+OF_2+H_2O\)
- (d)
\(2NO_2+20H^- \longrightarrow NO^-_2+NO^-_3+H_2O\)
Of the following elements, which one has the same oxidation state in all of its compounds?
- (a)
Hydrogen
- (b)
Fluorine
- (c)
Nitrogen
- (d)
Oxygen
What is the oxidation number of Man in \(K_2MnO_4?\)
- (a)
4
- (b)
5
- (c)
6
- (d)
7
In which of the following compounds, an element exhibits two different oxidation states?
- (a)
\(NH_2OH\)
- (b)
\(NH_2NO_3\)
- (c)
\(N_2H_4\)
- (d)
\(N_3H\)
The oxidation state of phosphorus varies from
- (a)
- 1 to + 2
- (b)
- 3 to + 3
- (c)
- 3 to + 5
- (d)
- 5 to + 1
The term 'X' in the following equation is \(2Fe^{3+}+Sn^{2+}\rightarrow 2Fe^{2+}+X\)
- (a)
\(Sn^{4+}\)
- (b)
\(Sn^{3+}\)
- (c)
\(Sn^{2+}\)
- (d)
\(Sn^{+}\)
Thiosulphate reacts differently with iodine and bromine in the reactions given below \(2S_2O^3_3+2Br_2+5H_2O\longrightarrow 2SO^{2-}_4+4Br^-+10H^+\) Which of the following statements justifies the above dual behaviour of thiosulphate?
- (a)
Bromine is a stronger oxidant than iodine
- (b)
Bromine is a weaker oxidant than iodine
- (c)
Thiosulphate undergoes oxidation by bromine and reduction by iodine in these reactions
- (d)
Bromine undergoes oxidation and iodine undergoes reduction in these reactions
Which of the following arrangement represents increasing oxidation number of the central atom?
- (a)
\(CrO^-_2,\ ClO^{3}_3,\ CrO^{2-}_4,\ MnO^-_4\)
- (b)
\(CrO^-_3,\ CrO^{2-}_4,\ MnO^-_4,\ CrO^-_2\)
- (c)
\(CrO^-_2,\ ClO^{-}_3,\ MnO^-_4, \ CrO^{2-}_4\)
- (d)
\(CrO^{2-}_4,\ MnO^-_4, CrO^-_2,\ ClO^-_3\)
A compound contains atom A, B and C. The oxdation number of A is + 2, of B is + 5 and of C is -2. The possible formula of the compound is
- (a)
ABC
- (b)
\(B_2(AC_3)_2\)
- (c)
\(A_3(BC_4)_2\)
- (d)
\(A_3(BC_3)_2\)
The oxidation number of chromium in potassium dichromate is
- (a)
+2
- (b)
+4
- (c)
+6
- (d)
+8
Which of the following is not an intermolecular redox reaction?
- (a)
\(MgCO_3\longrightarrow MgO+CO_2\)
- (b)
\(O_2+3H_2\longrightarrow 2H_30^+\)
- (c)
\(K+H_2O\longrightarrow KOH+({1\over 2})H_2\)
- (d)
\(MnBr_3\longrightarrow MnBr_2+{({1\over2})}Br_2\)
Which conversion is an oxidation?
- (a)
\(SO^{2-}_4\rightarrow SO^{2-}_3\)
- (b)
\(Cu^{2+}\rightarrow Cu\)
- (c)
\(H^+\rightarrow H\)
- (d)
\(H^-\rightarrow H\)
In the reaction \(3Cl_2+6NaOH\longrightarrow NaClO_3+5NaCl+3H_2O\) the element which loses as well as gains electrons is
- (a)
Na
- (b)
O
- (c)
Cl
- (d)
None of the above
In which of the following reactions, \(H_2O_2\) acts as a reducing agent?
I. \(H_2O_2+2H^+2e^-\longrightarrow 2H_2O\)
II. \(H_2O_2-2e^-\longrightarrow O_2+2H^+\)
III. \(H_2O_2+2e^-\longrightarrow 2OH^-\)
IV. \(H_2O_2+2OH^--2e^-\longrightarrow O_2+2H_2O\)
- (a)
I and II
- (b)
III and IV
- (c)
I and III
- (d)
II and IV
Consider the following reaction \(xMnO^-_4+yC_2O^{2-}_4+zH^+\longrightarrow xMn^{2+}+2yCO_2+{z\over 2}H_2O\) The values of x, y and z in the reaction respectively are
- (a)
5, 2 and 16
- (b)
2, 5 and 8
- (c)
2, 5 and 16
- (d)
5, 2 and 8
What product are expected from the disproportionation reaction of hypochlorous acid?
- (a)
\(HClO_3\) and \(Cl_2O\)
- (b)
\(HClO_2\) and \(HClO_3\)
- (c)
\(HCl\) and \(Cl_2O\)
- (d)
\(HCl\) and \(HClO_3\)
The oxidation state of Cr in \([Cr(NH_3)_4\ Cl_2]^+\)
- (a)
0
- (b)
+1
- (c)
+2
- (d)
+3
Among the properties, A reducing, B oxidising C complexing the set of properties shown by \(CN^-\) ion towards metal species is
- (a)
A and B
- (b)
B and C
- (c)
C and A
- (d)
A, B and C
\(MnO^-_4\) is a good oxidising agent in different medium changing to \(\underset{1} Mno^-_4\longrightarrow \underset{2} Mn^{2+} \longrightarrow \underset{3} MnO^{2-}_{4} \longrightarrow \underset{4} MnO_2 \longrightarrow \underset{5} Mn_2O_3\)
Changes in oxidation number respectively, are
- (a)
1, 3, 4, 5
- (b)
5, 4, 3, 2
- (c)
5, 1, 3, 4
- (d)
2, 6, 4, 3
Which of the following is a redox reaction?
- (a)
\(NaCl+KNO_3\rightarrow NaNO_3+KCl\)
- (b)
\(CaC_2O_4+2HCl\rightarrow CaCl_2+H_2C_2O_4\)
- (c)
\(Ca(OH)_2+2NH_4Cl \rightarrow CaCl_2+2NH_3 +2H_2O\)
- (d)
\(2K[Ag(CN)_2]+Zn\rightarrow 2Ag+K_2[Zn(CN)_4]\)