Tag: metals

Quizzes (9) Questions (306)

Questions Related to metals

Multiple choice chemistry metals reaction of metals reactions of metals chemical properties of metals

On reaction with water, an active metal produces:

  1. oxygen

  2. nitric acid

  3. base

  4. metal hydroxide

  5. none of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
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 $

Multiple choice chemistry metals reaction of metals reactions of metals chemical properties of metals

Metals combine with oxygen to produce:

  1. neutral acid

  2. basic oxide

  3. acidic acid

  4. amphoteric oxide
Reveal answer Fill a bubble to check yourself
B Correct answer
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.,
$K _2O(s)+H _2O(l) \rightarrow 2KOH(aq)$)

Multiple choice chemistry metals reaction of metals reactions of metals chemical properties of metals

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

  1. Zinc

  2. Iron

  3. Calcium

  4. Magnesium
Reveal answer Fill a bubble to check yourself
A Correct answer
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)

Multiple choice chemistry metals reaction of metals reactions of metals chemical properties of metals

Metals oxides are:

  1. basic in nature

  2. electrovalent (ionic) in nature

  3. able to turn red litmus solution blue

  4. all of these
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

Multiple choice chemistry metals reaction of metals reactions of metals chemical properties of metals

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

  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
Reveal answer Fill a bubble to check yourself
D Correct answer
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 $Fe _3O _4$.

Multiple choice chemistry metals reaction of metals reactions of metals chemical properties of metals

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:

  1. $Al,Al(OH) _3 $ and $ H _2$
  2. Ag, AgOH and $H _2$
  3. K, KCl and $H _2$
  4. Na, NaOH and $H _2$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

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

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