Tag: metals

Questions Related to metals

On reaction with water, an active metal produces:

chemistry metals reaction of metals reactions of metals chemical properties of metals

  1. oxygen

  2. nitric acid

  3. base

  4. metal hydroxide

  5. none of the above

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Correct Option: D
Explanation:

The reactivity of active metals can be demonstrated by dropping pieces of $Li, Na, K$ into water. $Li$ reacts slowly with water, $Na$ reacts more rapidly and $K$ reacts violently. For a reaction between sodium and water, it can be divided into two halves. One-half reaction describes what happens when sodium atoms lose electrons. The other half describes what happens when water molecules gain these electrons. An overall equation is obtained for the reaction which shows the formation of metal hydroxide and evolution of hydrogen gas.
$2Na\left( s \right) +2{ H } _{ 2 }O\left( l \right) \rightarrow 2{ Na }^{ + }\left( aq \right) +2{ OH }^{ - }\left( aq \right) +{ H } _{ 2 }\left( g \right) \uparrow $

Metals combine with oxygen to produce:

chemistry metals reaction of metals reactions of metals chemical properties of metals

  1. neutral acid

  2. basic oxide

  3. acidic acid

  4. amphoteric oxide

Show answer
Correct Option: B
Explanation:
An oxide that combines with water to give an acid is termed as an acidic oxide. The oxide that gives a base in water is known as a basic oxide.
Generally Group 1 and Group 2 metals  form bases called base anhydrides or basic oxides e.g.,
$4K+O _2 \rightarrow 2K _2O$
Basic oxides are the oxides of metals. If soluble in water, they react with water to produce hydroxides (alkalies) e.g.,
$K _2O(s)+H _2O(l) \rightarrow 2KOH(aq)$)

Name one metal that will not react with cold water but will react with steam.

chemistry metals reaction of metals reactions of metals chemical properties of metals

  1. Zinc

  2. Iron

  3. Calcium

  4. Magnesium

Show answer
Correct Option: A
Explanation:

Zinc is a metal which doesnot react with cold water but reacts with steam. The chemical equation for the reaction can be written as:
$ Zn + H _{2}O \rightarrow ZnO + H _{2}$
         (steam)

Which of the following oxide is amphoteric in nature?

chemistry metals reaction of metals reactions of metals chemical properties of metals

  1. $Na _2O$

  2. $Li _2O$

  3. $K _2O$

  4. $BeO$

Show answer
Correct Option: D
Explanation:

Compounds which have the ability to react as both an acid or base are known as amphoteric in nature. 

$BeO$ is amphoteric in nature.

$Pb _3O _4$ a double oxide. is obtained by heating lead (II) oxide in air.

chemistry metals reaction of metals reactions of metals chemical properties of metals

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Lead oxide is prepared by calcination of lead II oxide in air at about 450 to 480C.
$6PbO+{ O } _{ 2 }\rightarrow { 2Pb } _{ 3 }{ O } _{ 4 }$

$\displaystyle xFe+yH _{2}O\rightarrow zFe _{3}O _{4}+wH _{2}$
What are x, y, z and w respectively ?

chemistry metals reaction of metals reactions of metals chemical properties of metals

  1. 1, 2, 3, 4

  2. 2, 3, 1, 2

  3. 3, 4, 1, 4

  4. 3, 3, 3, 3

Show answer
Correct Option: C
Explanation:

Reaction:
$\displaystyle 3Fe+4H _{2}O\rightarrow 1Fe _{3}O _{4}+4H _{2}$

Calcium is stored in kerosene.

chemistry metals reaction of metals reactions of metals chemical properties of metals

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

Sodium is a highly reactive metal of alkali group and on exposure to air it forms sodium hydroxide while calcium is not reactive in nature so it is not stored in kerosene.

Metals oxides are:

chemistry metals reaction of metals reactions of metals chemical properties of metals

  1. basic in nature

  2. electrovalent (ionic) in nature

  3. able to turn red litmus solution blue

  4. all of these

Show answer
Correct Option: D
Explanation:

Metal oxides typically contain an anion of oxygen in the oxidation state of -2. Oxides which are reacted only by acids are basic oxides. Metals form basic oxides so they can turn red litmus blue as it is alkaline in nature.

What happens when water vapour is passed over a red hot iron?

chemistry metals reaction of metals reactions of metals chemical properties of metals

  1. No reaction

  2. Oxygen and $Fe{(OH)} _{2}$ are produced

  3. Hydrogen and ${Fe} _{2}{O} _{3}$ are produced

  4. Hydrogen and ${Fe} _{3}{O} _{4}$ are produced

Show answer
Correct Option: D
Explanation:

The reaction takes place as

$3Fe + 4H _2O \rightarrow Fe _3O _4 + 4H _2$
so, on passing water vapour over hot red iron we get hydrogen and $Fe _3O _4$.

A silvery-white metal $X$ reacts with water at room temperature to produce a water-soluble compound $Y$ and a colourless gas $Z$. The reaction is highly exothermic and the $Z$ catches fire immediately during the reaction. The solution of $Y$ in the water on reacting with a stoichiometric amount of dilute solution of hydrochloric acid gives a solution of $pH = 7.0$. 
The compounds $X,\ Y$ and $Z$ respectively are:

chemistry metals reaction of metals reactions of metals chemical properties of metals

  1. $Al,Al(OH) _3 $ and $ H _2$

  2. Ag, AgOH and $H _2$

  3. K, KCl and $H _2$

  4. Na, NaOH and $H _2$

Show answer
Correct Option: D
Explanation:

$2Na+H _2O\rightarrow 2NaOH+H _2+Heat$

$NaOH+HCl\rightarrow NaCl+H _2O$
$X,\ Y,\ Z$ are $Na$, $NaOH$, $H _2$