Tag: chemical bonding and structure

Quizzes (8) Questions (141)

Questions Related to chemical bonding and structure

Multiple choice chemistry chemical bonding and structure coordinate bond types of bonds and properties chemical bond and chemical equation

Which of the following types of solid is most likely to be soft, have low melting point and don't conduct electricity when melted?

  1. Ionic

  2. Molecular

  3. Covalent

  4. Metallic
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Covalent compunds are soft(due to presence of cloud of electrons between the bonding atoms), have low melting point(due to weak forces of attraction) and are bad conductors of electricity in the molten state(due to lack of free electrons)

Multiple choice chemistry chemical bonding and structure coordinate bond types of bonds and properties chemical bond and chemical equation

In the coordinate covalency,

  1. electrons are equally shared by the atoms

  2. electrons of one atom are shared between the two atoms

  3. hydrogen bond is formed

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

The 2 electrons of an atom( generally lone pair) is donated by one atom to the other atom and it results in the formation of a coordinate bond.

Multiple choice chemistry chemical bonding and structure coordinate bond types of bonds and properties chemical bond and chemical equation

During the formation of hydronium ion, water molecule acts as donor.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A hydronium ion is written as ${ H } _{ 3 }{ O }^{ + }$. 

It is formed when something else donates a proton, or $H^+$ to a water molecule.
The $H^+$ will easily bond to one of the two lone pairs of electrons around the water molecule.

     ${ H }^{ + }+{ H } _{ 2 }O\longrightarrow { H } _{ 3 }{ O }^{ + }$

Multiple choice chemistry chemical bond and chemical equation coordinate bond types of bonds and properties chemical bonding and structure

Which response includes only the true statements concerning the characteristics of covalent compounds?
$I$. These compounds can be gases, liquids, or solids with low melting points.
$II$. Most are soluble in polar solvents.
$III$. Liquid and molten compounds do not conduct electricity.
$IV$. Aqueous solutions of these compounds are very good conductors of electricity.

  1. $I$ and $III$
  2. $II$ and $IV$
  3. $I,III$ and $IV$
  4. $I,II$ and $III$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

I , II and III statement about covalent compounds are correct but the IV one is not correct since the aqueous solution of the covalent compound do not contain free ions and thus are not the good conductors of electricity .

Multiple choice chemistry chemical bonding and structure coordinate bond types of bonds and properties chemical bond and chemical equation

The pH of pure water at 25°C and 35°C are 7 and 6 respectively. The heat of formation  of water from ${H^ - }$  and $O{H^ - }$ will be :

  1. -77.11

  2. -84.55

  3. -92.36

  4. -66.25
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The auto-ionization of water is H2O <-> H+ + OH-. The heat of formation is related to the change in equilibrium constant (Kw) with temperature. The value -77.11 kJ/mol is the standard enthalpy change for this process.

Multiple choice chemistry chemical bond and chemical equation coordinate bond types of bonds and properties chemical bonding and structure

Dative bond is present in the molecule :

  1. $NH _3$
  2. $CO _2$
  3. $NaCl$

  4. None of these.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
A dative bond is a covalent bond between two atoms where one of the atoms provides both electrons that form the bond i.e. a kind of 2-center, 2-electron bond.

Here, covalent bond is present in $NH _3$ and $CO _2$, whereas ionic bond is present in $NaCl$.

So, there is no dative bond in  $NH _3$, $CO _2$ and $NaCl$.

Hence, option (D) is the correct answer.
Multiple choice chemistry chemical bonding and structure coordinate bond types of bonds and properties chemical bond and chemical equation

If pure $'p'$ orbitals are involved in molecule formation, then the shape of ${ H } _{ 3 }{ O }^{ + }$ will be:

  1. pyramidal

  2. tetrahedral

  3. angular

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

$ H _3O^+$ will have three bond pairs and one lone pair and shape same as $NH _3$ is therefore pyramidal. The hydroxonium ion is isoelectronic with ammonia and has an identical shape of pyramidal. 

So option $A$ is the correct option. 

Multiple choice chemistry chemical bonding and structure coordinate bond types of bonds and properties chemical bond and chemical equation

The dative bond is present in:

  1. $NH _{3}$
  2. $NH _{4}Cl$
  3. $PCl _{5}$
  4. $BF _{3}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When ammonium is formed, the fourth hydrogen is formed is attached by dative covalent bond because the only hydrogen nucleus is transferred from chlorine to nitrogen. The hydrogen electron left behind on the chlorine to form the negative chloride ion.

Multiple choice chemistry chemical bond and chemical equation coordinate bond types of bonds and properties chemical bonding and structure

Which of the following property is commonly exhibited by a covalent compound?

  1. High solubility in water

  2. Low melting point

  3. High electrical conductance

  4. High boiling point
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Covalent compounds are very resistant, they do not conduct heat and electricity, mostly insulators. They have low boiling points as they are gases at room temperature. It is very hard to molten the covalent compounds because of high bond energy. Therefore the covalent compound turns liquid from solid state easily. They show low melting points and are non polar hence insoluble in water.