Tag: chemistry

Quizzes (490) Questions (9892)

Questions Related to chemistry

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

Gases are separated from each other by:

  1. fractional evaporation

  2. fractional distillation

  3. fractional crystallisation

  4. fractional sublimation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Gases can be separated by fractional distillation. Firstly, the mixture is cooled until it forms a liquid. This is followed by heating it. The gas with lower boiling point rises in the distillation column & is thus separated.
Multiple choice chemistry reactivity series and electrochemistry reactivity series and displacement reactions chemical properties of metals chemical properties of metals and non metals

The most active halogen is:

  1. fluorine

  2. chlorine

  3. bromine

  4. none of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The most active halogen is fluorine. This is due to the small size and high electronegativity of Fluorine.

Fluorine, a pale yellow gas, is the least dense and chemically the most active, displacing the other halogens from their compounds and even displacing oxygen from water. Chlorine, a yellow-green gas, is denser and less reactive than fluorine.

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

Intensity of reaction of a metal with water depends upon its :

  1. mass number of metal

  2. chemical reactivity

  3. atomic no. of metal

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Metals react with water to form a metal hydroxide or metal oxide and hydrogen gas. Intensity of reaction depends upon its chemical reactivity.

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

$Li$, $K$, $Ca$, $Na$, $Mg$, $Al$, $Zn$, $Fe$, $Pb$, $Cu$, $Hg$, $Ag$
Which metal will displace hydrogen from acids but not water?

  1. $Li$
  2. $Na$
  3. $Cu$
  4. $Al$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Aluminium doesn't react with water because, a thin oxidise layer is formed on it. But it reacts with acid and displace Hydrogen in it. Because, The acid react with acidic layer and remove it from Aluminium.  

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

Which of the following statements is wrong?

  1. $F _{2}$ is the strongest oxidising agent as its reduction potential is high
  2. $Li$ is the weakest reducing agent as its reduction potential is low
  3. $Li$ is the strongest reducing agent as its reduction potential is high
  4. $F^{-}$ ion does not show reducing property
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

$Li$ is the strongest reducing agent as its reduction potential is low $(-3.05)$.

So, statement of option C is incorrect.

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

Which one of the following reactions does not occur?

  1. ${ F } _{ 2 }+2{ Cl }^{ - }\rightarrow 2{ F }^{ - }+{ Cl } _{ 2 }$
  2. ${ Cl } _{ 2 }+2{ F }^{ - }\rightarrow 2{ Cl }^{ - }+{ F } _{ 2 }$
  3. ${ Br } _{ 2 }+2{ I }^{ - }\rightarrow 2{ Br }^{ - }+{ I } _{ 2 }$
  4. ${ Cl } _{ 2 }+2{ Br }^{ - }\rightarrow 2Cl^-+{ Br } _{ 2 }$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

With progressive increase in atomic number, the reduction potential of halogens decreases, thus oxidising power also decreases. Hence, a halogen with lower atomic number will oxidise the halide ion of higher atomic number and therefore, will liberate them from their salt solution.
Hence, the reaction
${ Cl } _{ 2 }+2{ F }^{ - }\rightarrow 2{ Cl }^{ - }+{ F } _{ 2 }$
is not possible.

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

A list of common metals arranged in order of their decreasing reactivity is known as:

  1. activity series

  2. reactivity series

  3. conductivity series
  4. both $A$ and $B$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

An activity series is a list of substances ranked in order of relative reactivity. The most active metals are at the top of the table and least reactive at the bottom of the table. In chemistry, a reactivity series (or activity series ) is an empirical, calculated, and structurally analytical progression of series of metals, arranged by their reactivity from highest to lowest.