Chemistry

Chemical Compounds and Reactions

505 Questions

Chemical compounds and reactions involve understanding the properties, colors, and formation of various chemical substances. Questions focus on identifying precipitates, observing color changes during reactions, and naming common compounds. This topic is a fundamental part of the chemistry syllabus for competitive exams.

identifying precipitateschemical reaction colorscompound namingcolloidal particle propertiesacid base reactions

Chemical Compounds and Reactions Questions

Multiple choice aluminium patterns and properties of metals chemistry

The hydroxide, which is soluble in excess of sodium hydroxide is:

  1. $Fe(OH) _{3}$
  2. $Cu(OH) _{2}$
  3. $Cr(OH) _{3}$
  4. $Al(OH) _{3}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Aluminium hydroxide is insoluble in $H _2O$ but it is soluble in strong acids and strong bases. This is because of $Al(OH) _3$ its amphoteric nature.

$Al(OH) _3 + NaOH \rightarrow Na[Al(OH) _4]$

Multiple choice aluminium patterns and properties of metals chemistry

The incorrect statement among the following is:

  1. Bleaching powder is used as a germicide

  2. Chlorine is used in the preparation of

    insecticides like DDT.

  3. Fluorine is used in Rocket fuels
  4. $Na _{3}AlF _{3}$ is not a insecticide
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$Na _{3}AlF _{3}$ is used as a insecticide
So D is false

Multiple choice carbon tetrachloride ddt preparation of haloalkanes halogen derivatives

What happens when $C{Cl} _{4}$ is treated with $Ag{NO} _{3}$ solution?

  1. ${NO} _{2}$ is evolved
  2. A white precipitate of $AgCl$ is formed
  3. $C{Cl} _{4}$ will dissolve in $Ag{NO} _{3}$ solution

  4. No reaction
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$C{Cl} _{4}$ is a covalent compound, so it does not react with $Ag{NO} _{3}$

Multiple choice salts salts and their classification acids, bases and salts chemistry

When the aqueous solution of silver nitrate and sodium chloride are mixed, a________ precipitate is immediately formed.

  1. yellow

  2. white

  3. red

  4. black
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When silver nitrate $(AgNO _3)$ reacts with sodium chloride $(NaCl)$ a white precipitate of silver chloride $(AgCl)$ is formed which is highly insoluble in water, along with formation of sodium nitrate $(NaNO _3)$.

Since $(AgCl)$ is insoluble in water it will precipitate out and $(NaNO _3)$ is soluble in water so it will remain dissolved in the mixture. This reaction is an example of double displacement reaction and it occurs as follows:-
$AgNO _3\ +\ NaCl \rightarrow AgCl\ +\ NaNO _3 $
Hence, the correct answer is the option (B).

Multiple choice salts salts and their classification acids, bases and salts chemistry

A and B are two salts. A with dil. HCI and A and B with conc. ${H _2}S{O _4}$react to give reddish brown vapours, hence A and B respectively are:

  1. $NaN{O _3},NaBr$
  2. $NaBr,NaN{O _3}$
  3. $NaBr,NaN{O _2}$
  4. $NaN{O _{2,}}NaBr$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Bromide salts (NaBr) react with conc. H2SO4 to produce reddish-brown bromine vapors. Nitrates (NaNO3) react with conc. H2SO4 to produce reddish-brown NO2 gas upon heating. Since A reacts with dil. HCl, it must be the bromide (as nitrates do not react with dil. HCl).

Multiple choice salts salts and their classification acids, bases and salts chemistry

Ashish mixed a solution of soluble silver nitrate and soluble sodium chloride. The products formed are :

  1. soluble silver chloride and soluble sodium nitrate

  2. insoluble silver chloride and insoluble sodium nitrate

  3. insoluble silver chloride and soluble sodium nitrate

  4. soluble silver chloride and insoluble sodium nitrate
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

To make an insoluble salt, it is possible to make two soluble salts react together in a precipitation reaction. Silver nitrate and sodium chloride are both soluble. When mixing their solutions together, the result is insoluble silver chloride and soluble sodium nitrate.

Multiple choice salts salts and their classification acids, bases and salts chemistry

What is the state of a precipitated compound?

  1. $(l)$
  2. $(g)$
  3. $(aq)$
  4. $(s)$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Precipitation is the formation of solid from a solution. When the reaction occurs in a liquid solution, the solid formed is called the 'precipitate'. The chemical that causes the solid to form is called the 'precipitant'.

Multiple choice chemistry materials we use soap and detergents soap soap and detergent

Ordinary gasoline (petrol) that is used as fuel cars, scooters and automobiles contain many different chemicals that are added in small quantities, each performing an important role. Some of these are mentioned here. Which of the option is false?

  1. Soaps used for removing particles of grease from petrol tanks ensure a free flow of petrol

  2. Anti-icing agents are used for depressing the freezing point of particles of ice

  3. Anti-rust agents are used for protecting against corrosion by water

  4. Detergents are used for preventing gums from sticking on the walls of the carbureter
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$\bullet$ Anti- rust agents are used for protecting iron materials against corrosion by water. Example- Redoxide.

$\bullet$ Anti-icing agents are used for depressing the freezing point of particles of ice.
$\bullet$ Soaps only grease particles from clothes, but it can't remove grease from petrol.

Multiple choice chemistry group 17 group 17 - physical properties physical properties of group 17 elements group 17 elements: the halogen family

The colour of iodine is:

  1. violet

  2. green

  3. white

  4. brown
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Iodine has atomic number 53 belonging to group 17. The name is from Greek meaning violet or purple due to the colour of elemental iodine vapour. It is a bluish-black solid with a metallic lustre sublimating into violet-pink gas and colour is due to absorption of visible light by an electronic transition between highest and lowest molecular orbitals.

Multiple choice chemistry p- block elements-i study of aluminium chloride study of aluminium structure of some compounds

Which of the following will be formed, if we heat an aqueous solution of $AlCl _3$ to dryness?

  1. Solid $AlCl _3$
  2. Dimer $Al _2Cl _6$
  3. $Al(OH) _3$
  4. $Al _2O _3$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

We knoe $AlCl _3$ exists as a dimer $Al _2Cl _6$

The reactions involved are given by,
$Al _2Cl _6 .6H _2O \rightarrow Al _2O _3+3H _2O+6HCl$
So,option D is correct answer.