Chemistry

Chemical Bonding and Molecular Structure

1,420 Questions

This section tests your knowledge of chemical bonding, molecular structure, and hybridization. It covers ionic and covalent bonds, octet rule exceptions, and molecular geometry. These chemistry questions are common in various competitive entrance examinations.

Ionic and covalent bondsHybridisation of elementsOctet rule exceptionsMolecular geometryIntermolecular forces

Chemical Bonding and Molecular Structure Questions

Multiple choice chemistry water drying and dehydrating agents hydrolysis of salts and the ph of their solutions chemical equilibrium and acids-bases

Which of the following is deliquescent?

  1. $ZnCl _2$
  2. $Hg _2Cl _2$
  3. $HgCl _2$
  4. $CdCl _2$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$(A)$  $ZnCl _{2}$


$Reason$ : Zinc chloride is a chemical compound with the formula $ZnCl _{2}$ and its hydrates.All zinc chlorides are colourless or white and highly soluble in water.Zinc chloride or $ZnCl _{2}$ is a $deliquescent$ salt  and forms acidic solutions in polar organic solvents,such as water, ether and acetone etc.
As we know, $deliquescent$ substances are the water soluble substances which absorbs moisture from the air and then dissolve in the absorbed moisture to change into liquid state and this phenomenon is called $deliquescence$.$ZnCl _{2}$ is one of the example of $deliquescent$ substance.

Multiple choice chemistry water drying and dehydrating agents hydrolysis of salts and the ph of their solutions chemical equilibrium and acids-bases

Which of the following salts can produce only two types of radicals?

  1. $NaKCO _3$
  2. $CaOCl _2$
  3. $NH _4HSO _4$
  4. $Na(NH _4)HPO _4$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

$NaKCO _3\rightarrow Na^++K^++CO _{3}^{-2}$
$CaOCl _2\rightarrow Ca^{+2}+OCl^-+Cl^-$
$NH _4HSO _4\rightarrow NH _{4}^{+}+HSO _{4}^{-}$
(2 types of radicals)
$Na(NH _4)HPO _4\rightarrow Na^++NH _{4}^{+}+HPO _{4}^{-}$

Multiple choice biology multicellular structure: tissue muscle tissue structure of protein muscle tissues

Chemical ions responsible for muscle contraction are

  1. ${ Ca }^{ ++ }$ and ${ K }^{ + }$
  2. ${ Na }^{ + }$ and ${ K }^{ + }$
  3. ${ Na }^{ + }$ and ${ Ca }^{ ++ }$
  4. ${ Ca }^{ ++ }$ and ${ Mg }^{ ++ }$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Calcium ions play a significant role in the muscle contraction. These activate the interaction of myosin and actin, through the intervention of tropomyosin and troponin.
Magnesium, in muscle contraction, stimulates calcium re-uptake by the calcium-activated ATPase of the sarcoplasmic reticulum. It also affects the translocation of calcium ions through the smooth muscle cell membrane.

Multiple choice biology natural disasters: winds, storms and cyclones composition of air introduction to air natural resources - air

Which of the following compounds produce $N _2$ on strong heating?

  1. $NaNO _2$
  2. $NaNO _3$
  3. $NH _4NO _2$
  4. $AgNO _3$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The thermal decomposition of sodium nitrite to produce sodium oxide(III), nitrogen and oxygen. This reaction takes place at a temperature of $700-900°C.$

$4NaN{ O } _{ 2 }→2{ Na } _{ 2 }O+2{ N } _{ 2 }+3{ O } _{ 2 }$

Multiple choice enzymes and catalysts catalysis adsorption and colloids surface chemistry chemistry adsorption theory of heterogeneous catalysis

Which acts as poison for Pd-charcoal in Lindlar's catalyst?

  1. $BaSO _4$

  2. Quinoline
  3. Both $A$ and $B$

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

A Lindlar catalyst is a heterogeneous catalyst which  consists of palladium deposited on calcium carbonate which is then poisoned with various forms of lead or sulphur not with $BaSO _4$ and quiniline. It is used for the hydrogenation of alkynes to alkenes.

Multiple choice chemistry chemical changes electrochemical reactions electrolysis and its applications electrolytic cells and electrolysis

The electrolysis of which electrolyte gives the same products in the fused state as well as in the aqueous solution state?

  1. NaCl

  2. KCl
  3. AuCl$ _{3}$
  4. BaCl$ _{2}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

All have $Cl^-$ ions, $\therefore  Cl _2$, is released at anode
The element with reduction potential > red. potential of $H^+$ will give same results for aqueous and molter states.
From the given options only $SRP  of  Au^+  >  SRP  of  H^+$
Hence, for other salts in their aqueous solutions $H^+$  gets reduced

Hence, option C is correct.

Multiple choice chemistry chemical changes electrochemical reactions electrolysis and its applications electrolytic cells and electrolysis

Aqueous solution of nickel sulphate contains $Ni^{2+}$ and ${SO _{4}}^{2-}$ ions. Which ion moves towards the cathode?

  1. $Ni^{2+}$
  2. ${SO _{4}}^{2-}$

  3. both A and B

  4. none of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
 Reaction at cathode (Reduction)  Reaction at Anode (Oxidation)
 Ions at cathode : $Ni^{2+} , H^+$ Preferential discharge of $Ni^{2+}$ ions takes place. $Ni^{2+} (aq) + 2e^- \rightarrow Ni^0(s)$Nickel metal deposits on the article. i.e. nail.  Ions at anode : $SO _4^{2-} , OH^-$$Ni^0 (s) - 2e^- \rightarrow Ni^{2+} (aq)$$Ni^{2+}$ ions are formed at anode.

None of the above ions discharge at anode ; instead Ni atoms of the anode lose electrons to form $Ni^{2+}$ ions.