Q.1
State the reducing agent in this reaction.Cu + 4HNO -> Cu(NO3)2 + 2H+ 2NO2
  • Cu
  • HNO3
  • Cu(NO3)2
  • NO2
Q.2
Check all the equations whereby the underlined substances has been oxidized.
  • iron (II) oxide + aluminium -> aluminium oxide + iron
  • hydrogen + oxygen -> water
  • Both A & B
  • copper (II) oxide + ammonia -> copper + nitrogen + water
Q.3
Name the oxidising agent in the following reaction:nitrogen + hydrogen -> ammonia
  • nitrogen
  • hydrogen
  • ammonia
Q.4
The ionic equation shows the reaction between zinc (Zn) and hydrochloric acid.Zn + 2H+ -> Zn+ H2What change takes place in the zinc?
  • It gains electrons
  • Its oxidation state increases
  • It is reduced
  • It gains hydrogen
Q.5
When a gas changes iron (III) oxide to iron (II) oxide, it shows that the gas is
  • a reducing agent
  • an oxidizing agent
  • a combustible gas
  • a diffusible gas
Q.6
In the reaction, Fe2O3(s) + 3CO(g) → 2Fe(l) + 3CO2(g)
  • carbon monoxide is reduced
  • carbon monoxide is the oxidising agent
  • iron(III) oxide is oxidised
  • iron(III) oxide is the oxidising agent
Q.7
(a) Zn2+(aq) + 2e- -> Zn(s) -0.76(b) Cr3+(aq) + 3e- -> Cr(s) -0.(c) Fe2+(aq) + 2e- -> Fe(s) -0.41correct decreasing order of reducing agents is
  • a>b>c
  • b>a>c
  • c>a>b
  • c>b>a
Q.8
Name the following ionic compound: Cs2S
  • cesium sulfide
  • cesium sulfate
  • cesium (II) sulfate
  • cesium (II) sulfide
Q.9
A compound having +2 oxidation state of O is
  • H2O
  • H2O2
  • OF2
  • O2F2
Q.10
Which problem is balanced?
  • PbO2 + 2H2
  • SO2 + H20 --> H2SO4
  • 2Na + 2H2O --> 2NaOH + H2
Q.11
H2O2--> H+O2 is an example of
  • displacement reaction
  • combination reaction
  • decomposition reaction
  • disproportionation reaction
Q.12
In a voltaic cell electrons flow
  • through the salt bridge
  • from the cathode to the anode through the wire
  • from the anode to the cathode through the wire
Q.13
Which energy conversion shown below takes place in a voltaic cell?
  • Electrical to chemical
  • Mechanical to chemical
  • Mechanical to electrical
  • Chemical to electrical
Q.14
An increase in oxidation number.
  • more acidic
  • reduction
  • less basic
  • oxidation
Q.15
What is oxidation number of H in CaH2?
  • +1
  • -1
  • 0
  • +2
Q.16
What is oxidation number of Cr in Cr2O72-?
  • -2
  • +2
  • +6
  • +12
Q.17
The basis of redox reactions is the
  • change in oxidation numbers
  • recombination of atoms in molecules
  • loss, gain, or bias of electrons
  • gain or loss of oxygen atom
Q.18
Bordo mix that is used in agriculture cannot be held in an iron container because iron reacts with the copper (II) sulphate. In the reaction, iron
  • is an oxidising agent
  • is a reducing agent
  • has a decrease in oxidation number
  • is reduced
Q.19
The correct description about redox reaction is
  • Oxygen is definitely present
  • The oxidising agent itself carries out oxidation
  • Oxidation takes place before reduction
  • Electron transfer definitely takes place
Q.20
Which one below is redox reaction?
  • CaCO3+2HCl⟶CaCl2+CO2+H2OCaCO_3+2HCl\longrightarrow CaCl_2+CO_2+H_2OCaCO3​+2HCl⟶CaCl2​+CO2​+H2​O
  • CaO+H2O⟶Ca(OH)2CaO+H_2O\longrightarrow Ca\left(OH\right)_2CaO+H2​O⟶Ca(OH)2​
  • SO2+2H2S⟶3S+2H2OSO_2+2H_2S\longrightarrow3S+2H_2OSO2​+2H2​S⟶3S+2H2​O
  • NaCl+AgNO3⟶AgCl+NaNO3NaCl+AgNO_3\longrightarrow AgCl+NaNO_3NaCl+AgNO3​⟶AgCl+NaNO3​
0 h : 0 m : 1 s