Tag: reactivity series and electrochemistry

Questions Related to reactivity series and electrochemistry

X, Y, Z are three elements which undergo chemical changes according to the following equations:
$I:\, X _2O _3 + 2Y \rightarrow Y _2O _3 + 2X$
$II:\, Y _2O _3 + 3Z \rightarrow 3ZO + 2Y$
The order of increasing reactivity is:

chemistry reactivity series and electrochemistry reactivity series and displacement reactions chemical properties of metals chemical properties of metals and non metals

  1. X < Y < Z

  2. Y < X < Z

  3. Z < X < Y

  4. Z < Y < X

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Correct Option: A
Explanation:

Y has displaced X in reaction I. So, Y is more reactive than X.
Z has displaced Y is reaction II. So, Z is more reactive than Y. 

Thus, Z is most reactive and X is the least reactive.

Which of the following statement is incorrect?

chemistry reactivity series and electrochemistry reactivity series and displacement reactions chemical properties of metals chemical properties of metals and non metals

  1. Metals like $Cu, Ag, Au$ cannot displace $H$ from acids

  2. In reactivity series metals are arranged in order of increasing reactivity

  3. Silver cannot displace $Cu$ form $Cu(NO _3) _2$

  4. Zinc displaces $Cu$ from $CuSO _4$

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Correct Option: B
Explanation:

In activity series metals are arranged in decreasing order of reactivity. The metals present at top of the series are highly reactive while metals present at the bottom are relatively inert in nature.

Metals which loses electrons more easily than hydrogen are more reactive than $H _2$ and they can :

chemistry reactivity series and electrochemistry reactivity series and displacement reactions chemical properties of metals chemical properties of metals and non metals

  1. not displace $H _2$ from dilute acids

  2. displace hydrogen from dilute acids

  3. not react with water easily

  4. none of these

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Correct Option: B
Explanation:

Metals present on top of the reactivity series above the hydrogen can displace the metals present below them from their salt solution.

Iron can displace ________ from its solution.

chemistry reactivity series and electrochemistry reactivity series and displacement reactions chemical properties of metals chemical properties of metals and non metals

  1. $Cu$

  2. $Al$

  3. $Zn$

  4. $Mg$

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Correct Option: A
Explanation:

Iron can displace $Cu$ from its solution

Reactivity series: Highest $\longrightarrow$ Lowest
$K>Na>Ca>Mg>Al>Zn>Fe>Sn>Pb>Cu>Ag>Au$
Highly reactive elements can displace less reactive elements from their solution.

Copper can be displaced from aqueous solution of copper sulphate by adding:

chemistry reactivity series and electrochemistry reactivity series and displacement reactions chemical properties of metals chemical properties of metals and non metals

  1. $Ag$

  2. $Au$

  3. $Pt$

  4. $Fe$

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Correct Option: D
Explanation:

$Fe(s)+CuSO _4(aq)\longrightarrow Cu(s)+FeSO _4(aq)$

Metals like $Zn, Pb, Fe$ and $Al$, displace $Cu$ from copper salt solution.
Reactivity series of metals: $K>Na>Ca>Mg>Al>Zn>Fe>Sn>Pb>Cu>Ag>Au$
So, $K$ is most reactive and $Au$ is least reactive. Metals which are more reactive than that element can displace that element from its salt solution.

An element is oxidized by fluorine but not by chlorine, could this element is oxidized?

chemistry reactivity series and electrochemistry reactivity series and displacement reactions chemical properties of metals chemical properties of metals and non metals

  1. Sodium

  2. Sulphur

  3. Oxygen

  4. Aluminium

Show answer
Correct Option: C
Explanation:

Oxygen is the second most electronegative element in the periodic table and has electronegative value 3.5. So, it creates polarity that strongly attract the electron towards itself.

Identify the metals seen in middle of reactivity series.
a) Zinc, b) Lead c) Iron d) Copper

chemistry reactivity series and electrochemistry reactivity series and displacement reactions chemical properties of metals chemical properties of metals and non metals

  1. a, b

  2. b, c

  3. a, c, d

  4. All of the above

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Correct Option: D
Explanation:

Metals in the middle of the activity series are iron, zinc, lead, copper etc. 

If $A, B, C, D, E, F, G, H, I, J, K$ represents metals in the decreasing order of their reactivity, which one of item is most likely, to occur in a free state in nature?

chemistry reactivity series and electrochemistry reactivity series and displacement reactions chemical properties of metals chemical properties of metals and non metals

  1. A

  2. C

  3. J

  4. K

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Correct Option: D
Explanation:

Metal higher in the activity series is said to be more metallic than another which is below and the metals at the top of the activity series are so reactive that they are never found in nature in free state.

Mark the incorrect statement.

chemistry reactivity series and electrochemistry reactivity series and displacement reactions chemical properties of metals chemical properties of metals and non metals

  1. Reactive metals can displace less reactive metals from their compounds in solution

  2. All metals are not equally reactive

  3. Both A and B

  4. None of the above

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Correct Option: D
Explanation:

Reactive metals can displace less reactive metals from their compounds in solution or molten form. All metals are not equally reactive. Their reactivity is different for different metals.

Which of the following oxides can't be reduced by carbon?

chemistry reactivity series and electrochemistry reactivity series and displacement reactions chemical properties of metals chemical properties of metals and non metals

  1. Sodium, magnesium, calcium, aluminium

  2. Sodium, potassium, tin, lead

  3. Both A and B

  4. None of the above

Show answer
Correct Option: A
Explanation:

Carbon cannot reduce the oxides of sodium, magnesium, calcium, aluminium etc. to the respective metals. This is because these metals have more affinity for oxygen than carbon.