Electrochemical Series

Q. Divide the following redox reactions into oxidation and reduction half reactions.​
Zn + $C{u}^2+$ → $Z{n}^2+$ + Cu​

Q. What happens when a copper wire is dipped in a ferrous sulphate solution?

Q. A reducing agent is a substance which can

1. accept electrons
2. donate electrons
3. accept protons
4. donate protons

Q.

Which element acts as strong reducing agent?

Q.

Which of the following is not a method for purification of metals:

1. Calcination

2. Distillation

3. Liquation

4. Electrolytic refining

Q.

An aqueous solution containing one mole per litre of each $Cu(N{O}_3{)}_2,AgN{O}_3,H{g}_2(N{O}_3{)}_2$ and $Mg(N{O}_3{)}_2$, is being electrolysed by using inert electrodes. The values of standard electrode potentials in volts (reduction potentials) are $Ag/A{g}^{+}=+0.80,2Hg/H{g}_2^{2+}=+0.79,Cu/C{u}^{2+}=+0.34,Mg/M{g}^{2+}=-2.37$

With increasing voltage, the sequence of deposition of metals on the cathode will be

1. Ag, Hg, Cu, Mg
2. Ag, Hg, Cu
3. Cu, Hg, Ag
4. Mg, Cu, Hg, Ag

Q.

The process of extraction of metal from its ores, is known as

1. concentration

2. calcination

3. purification

4. metallurgy

Q.

From the metals: copper, iron, magnesium, sodium, and zinc, select a different metal in each case which:

(a) does not react with dilute hydrochloric acid,

(b) can form $2^{+}$ and $3^{+}$ ions,

(c) has a hydroxide that reacts with both acids and alkalis,

(d) does not react with cold water but reacts with steam when heated.

(e) Arrange the above metals in their decreasing order of reactivity.

Q.

The impurities present in the ore are known by the name

1. flux

2. ore

3. gangue

4. slag

Q.

Which one of the following metals cannot be obtained on electrolysis of an aqueous solution of its salts?

1. Ag
2. Cu
3. Mg
4. Cr

Q.

Why fluorination is explosive?

Q.

Copper reduces into $\mathrm{NO}$ and ${\mathrm{NO}}_2$ depending upon the concentration of ${\mathrm{HNO}}_3$ in solution .(Assuming fixed $\left[{\mathrm{Cu}}^{2+}\right]$ and , $P_{\mathrm{NO}}=P_{N{O}_2}),$the ${\mathrm{HNO}}_3$ concentration at which the thermodynamic tendency for reduction of into $\mathrm{NO}$ and ${\mathrm{NO}}_2$ by copper is same is${10}^{\mathrm{x}}\mathrm{M}$

The value of $2\mathrm{x}$ is _____. (Rounded-off to the nearest integer $\mathrm{Cu}\left(\mathrm{s}\right)\to {\mathrm{Cu}}^{2+}+2{\mathrm{e}}^{-}$)

$$\begin{gathered} [\mathrm{Given}:{\mathrm{E}}_{{\mathrm{Cu}}^{2+}/\mathrm{Cu}}^0=0.34\mathrm{V},{\mathrm{E}}_{{{\mathrm{NO}}_3}^{-}/\mathrm{NO}}^0=0.96\mathrm{V},{\mathrm{E}}_{{{\mathrm{NO}}_3}^{-}/\mathrm{N}}^0\mathrm{and}\mathrm{at}298\mathrm{K} \\ \frac{\mathrm{RT}}{\mathrm{F}}(2.303)=0.059] \end{gathered}$$

Q. For the following cell:
$Zn\left(s\right)|ZnS{O}_4\left(aq\right)||CuS{O}_4\left(aq\right)\left)|Cu\right(s)$
When the concentration of $Z{n}^{2+}$ is 10 times the concentration of $C{u}^{2+}$, the expression for $\Delta G\left(inJmo{l}^{-1}\right)$ is
[F is Faraday constant; R Is gas constant; T is temperature ; $E^{\circ }\left(cell\right)=1.1v]$

1. 2.303 RT + 1.1 F
2. 2.303 RT - 2.2 F
3. 1.1 F
4. -2.2 F

Q. Divide the following redox reactions into oxidation and reduction half reactions.​

(iii) Cl${}_2$ + 2Br${}^{-}$ $\to$ Br${}_2$ + 2Cl${}^{-}$

Q.

The element A placed above element B in the electrochemical series can displace element B from its salt.

1. False

2. True

Q. Which of the following elements cannot displace hydrogen form $H_{2}S{O}_4$?

1. Fe
2. Cu
3. Zn
4. Na

Q. Divide the following redox reactions into oxidation and reduction half reactions.​

(v) 2Cu${}^{+}$ $\to$ Cu + Cu${}^{2+}$

Q. Bi(5) is stronger oxidizing agent than sb(5)

Q.

Copper can produce hydrogen on reacting with acids but zinc cannot.

1. True

2. False

Q.

An iron knife kept in blue copper sulphate solution turns the blue solution into light green. Explain. [2 MARKS]

Q.

How does the method used for extracting a metal from its ore depend on the metal's position in the reactivity series ? Explain with examples.

Q. $E_{A{g}^{+}|Ag}^{\circ }=0.8$ volt and $E_{Z{n}^{2+}|Zn}^{\circ }=-0.76$ volt

Which of the following is correct?

1. 
2. 
3. 
4. 

Q.

(a) Aluminium is a more active metal than iron, but suffers less corrosion. Why?
(b) Explain and give reasons why aluminium vessels should not be cleaned with powders containing alkalis.
(c) Why is the food containing iron salts should not be cooked in aluminium utensils?

Q. From the metals-copper, iron, magnesium, sodium and zinc-select a different metal in each case which :
(a) does not react with dilute hydrochloric acid.
(b) can form 2⁺ and 3⁺ ions.
(c) has a hydroxide that reacts with both acids and alkalis.
(d) does not react with cold water, but reacts with steam when heated.

Q.

Cobalt is _______ reactive than nickel.

Q. Based on the reactivity series, which of the following metals can be extracted by the process of electrolysis?

1. Gold
2. Zinc
3. Copper
4. Calcium

Q. What volume pf 3 molar hno3 is needed to oxidise 8g ferrous to ferric, hno3 gets converted to NO

Q.

(a) Name two gases which combine chemically to form a solid.
(b) Name a chloride which is soluble in excess of ammonium hydroxide.
(c) How will you show that hydrochloric acid contains both hydrogen and chlorine (other than by electrolysis)?
(d) Complete and balance the following equations:
KMnO₄ + HCl $\stackrel{}{\to }$ _______ + _______ + ________ + 8H ₂O

Q.

(a) Write a balanced equation for the reaction of zinc and dilute hydrochloric acid.
(b) State what is observed when hydrochloric acid is added to silver nitrate solution.

Q.

Which of the following is the strongest oxidizing agent?

1. E°(S₂O₈²⁻/SO₄²⁻) = 2.05 V

2. E° (Br₂/Br⁻) = 1.40 V

3. E° (Au³⁺/Au) = 1.10V

4. E° (O₂/H₂O) =1.20V