Tag: chemistry

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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.

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

"Hybridisation of central atom does not always change due to back bonding". This statement is valid for which of the following compounds ? 
(i) $CCl^- _3$                      (ii) $CCl _2$
(iii) $(SiH _3) _2 O$              (iv) $N(SiH _3) _3$

  1. (i), (ii)

  2. (i), (iii)

  3. (ii), (iii)

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

When there is back bonding from central to side atom change in hybridization takes place. Back bonding takes place when one atom has vacant orbital and one has lone pairs. 
So central atom has a lone pair and side atom must have vacant orbital 
So : $CCl^- _3$
$N (SiH _3) _3$
$Sp^3 - Sp^2$

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

Which of the following molecules does not have co-ordinate bonds?

  1. $PH _{4}^{+}$
  2. $NO _2$
  3. $O _3$
  4. $CO _{3}^{2-}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

CO3(2-) is a resonance-stabilized ion where the bonding is described by delocalized electrons. While it can be represented with coordinate bonds in Lewis structures, PH4+, NO2, and O3 clearly feature dative bonds in their standard representations.