Question 3 :
Iron is extracted from iron oxide using carbon monoxide as shown.<br>iron oxide + carbon monoxide $\rightarrow$ iron + carbon dioxide<br>Which statement is correct?

Question 4 :
When Carbon monoxide is passed over heated copper oxide it gives :<br/>

Question 5 :
How many moles of electrons are involved in the reduction of one mole of $MnO^-_4$ ion in alkaline medium to $MnO^-_3$?

Question 7 :
Out of the halogens, which one is the most powerful oxidizing agent?

Question 8 :
In which of the following reactions, does a non-metal act as a reducing agent?

Question 9 :
When Magnesium is burnt in air, a white ash remain as left over. What is this?

Question 10 :
Which of the statements about the reaction below are incorrect?<div><br/>$2PbO\left( s \right) +C\left( s \right) \rightarrow 2Pb\left( s \right) +C{ O }_{ 2 }\left( g \right) $</div><div><br/>(a) Lead is getting reduced.<br/>(b) Carbon dioxide is getting oxidised.<br/>(c) Carbon is getting oxidised.<br/>(d) Lead oxide is getting reduced.</div>

Question 11 :
Iron (III) oxide on heating with carbon monoxide gas form solid iron and liberates carbon dioxide gas. This is a:<br/>

Question 13 :
What is the oxidising agent in the following reaction?<br>$2Fe^{2+}_{aq} + Cl_{2(g)} \rightarrow 2Fe^{3+}_{(aq)} + 2Cl^-_{(aq)}$

Question 15 :
_______ is a degradation phenomenon in which the electrons in a plastic are so strongly attracted to oxygen atoms.

Question 16 :
Which of the following acts both as oxidising as well as reducing agent?

Question 18 :
Decolourisation of acidified potassium permanganate occurs when $H_{2}O_{2}$ is added to it. This is due to:

Question 22 :
Which one of the following reactions is not an example of redox reaction

Question 23 :
Statement 1: Oxidation and reduction occur together. <br/>Statement 2: In redox reactions, electrons must be gained and lost.

Question 26 :
The process of black and white photography depends&#160;upon the following reaction which is initiated by light.&#160;<div>$2Ag^+ + 2Br^-\rightarrow 2Ag + Br_2$<br/>Which of the following species is reduced in this reaction?<br/></div>

Question 27 :
$Al + MnO_4^- \rightarrow Al(OH)_4^- + MnO_2$<br>For this reaction, element $X$ is reduced and element Y is oxidised. Then $X$ and $Y$ are respectively:

Question 28 :
Consider the reaction: $Cl_{2} + 2KI \rightarrow I_{2} + 2KCl$<br>Which species will be reduced at the cathode?

Question 31 :
$\displaystyle CuO+{ H }_{ 2 }\longrightarrow { H }_{ 2 }O+Cu$, reaction is an example of :<br/>

Question 32 :
'a' g $ KHC_2O_4 $ required to reduce 100 mL of 0.02 M $ KMnO_4 $ in acid medium and 'b'&nbsp; g $ KHC_2O_4 $neutralises 100 mL of 0.05 $ M Ca(OH)_2 $ then&nbsp;

Question 33 :
Consider the following $E^{0}$ values:<br/>$E_{Fe^{3+}/Fe^{2+}}^{0}$ = 0.77V,<br/>$E_{Sn^{2+}/Sn}^{0}$ = -0.14V<div><br/>Under standard conditions the potential for the reaction, is:</div><div><br/><div>$Sn(s)+2Fe^{3+}(aq)\rightarrow 2Fe^{2+}(aq)+Sn^{2+}(aq)$</div></div>

Question 37 :
A dilute Ferrous sulphate solution was gradually added to the beaker containing acidified permanganate solution. The light purple colour of the solution fades and finally disappears. Which of the following is the correct explanation for the observation?

Question 38 :
$Al + NO_2^-&#160;&#160;\rightarrow Al(OH)_4^- + NH_3 $<br/>The oxidizing agent for this reaction is________.

Question 39 :
When the gases; sulphur dioxide and hydrogen sulphide mix in the presence of water, the reaction $ SO_2 + 2H_2 S \rightarrow 2H_2 O + 3S$ occurs.<br/>Here hydrogen sulphide is acting as :<br/>

Question 42 :
Which of the following behaves as both oxidising and reducing agents ?&#160;

Question 44 :
Which of the following reaction are disproportion reaction?<br/>a) $2Cu^+\rightarrow Cu^{2+}+Cu^o$<br/>b) $3MnO^{2-}_4+4H^+\rightarrow 2MnO_4^-+MnO_2+2H_2O$<br/>c) $2KMnO_4\xrightarrow []{\Delta}K_2MnO_4+MnO_2+O_2$<br/>d) $2MnO_4^-+3Mn^{2+}+2H_2O\rightarrow 5MnO_2+4H^{+}$

Question 45 :
A list of reactions are given below.<div><br/><div>(a) $Fe + 2 HCl \rightarrow FeCl_2 + H_2$</div><div><br/>(b) $FeS + 2HCl \rightarrow FeCl_2 &#160;+ H_2 S$</div><div><br/>(c) $Fe + S \xrightarrow{\Delta} FeS$</div><div><br/>(d) $NaCl + H_2SO_4 \xrightarrow{&lt; 200^o C} NaHSO_4 + HCl$</div><div><br/>(e) $CuSO_4 + H_2 S \rightarrow CuS + H_2SO_4$</div><div><br/>(f) $S + H_2SO_4 \rightarrow 3 SO_2 + H_2O$</div><div><br/></div><div>Identify redox reactions.</div></div>

Question 46 :
Fill in the blanks by picking the option with appropriate words.&nbsp;<br>Oxidising agent is a substance which <u>P</u> itself and <u>Q</u> the other. Reducing agent is a substance which <u>R</u> itself and <u>S</u> the other. The reactions which involve be oxidation and reduction are called <u>T</u> reactions.<span><br></span>

Question 48 :
Which one of the following reactions is an example of redox reaction ?