Lakhmir Singh and Manjit Kaur Solutions for Chapter: Carbon And its Compounds, Exercise 5: Questions Based on High Order Thinking Skills (HOTS)

An element E exists in three allotropic forms A, B and C. In allotrope A, the atoms of element E are joined to form spherical molecules. In allotrope B, each atom of element E is surrounded by three other E atoms to form a sheet like structure. In allotrope C, each atom of element E is surrounded by four other E atoms to form a rigid structure.
(a) Name the element E.
(b) What is allotrope A?
(c) What is allotrope B?
(d) What is allotrope C?
(e) Which allotrope is used in making jewellery?
(f) Which allotrope is used in making anode of a dry cell?

You are given the following molecular formulae of some hydrocarbons: 

${\mathrm{C}}_5{\mathrm{H}}_8; {\mathrm{C}}_7{\mathrm{H}}_{14}; {\mathrm{C}}_6{\mathrm{H}}_6; {\mathrm{C}}_5{\mathrm{H}}_{10}; {\mathrm{C}}_7{\mathrm{H}}_{12}; {\mathrm{C}}_6{\mathrm{H}}_{12}$

(a) Which formula represents cyclohexane as well as hexene?
(b) Which formula represents benzene?
(c) Which three formulae represent open chain unsaturated hydrocarbons having double bonds?
(d) Which two formulae represent unsaturated hydrocarbons having triple bonds?
(e) Which three formulae can represent cyclic hydrocarbons?
 

Which of the following compounds can have a triple bond?

${\mathrm{C}}_2{\mathrm{H}}_4; {\mathrm{C}}_3{\mathrm{H}}_4; {\mathrm{C}}_3{\mathrm{H}}_6$

Write the molecular and structural formula of a cyclic hydrocarbon whose molecule contains 8 atoms of carbon.

 What is the molecular formula and structural formula of a cyclic hydrocarbon whose one molecule contains $8$ hydrogen atoms?

Write the molecular formula of: (i) an alkane (ii) an alkene, and (iii) an alkyne, each having 20 carbon atoms.

Which of the following compounds can have a double bond?
$\left(\mathrm{a}\right){\mathrm{C}}_4{\mathrm{H}}_{10}; \left(\mathrm{b}\right){\mathrm{C}}_5{\mathrm{H}}_{12}; \left(\mathrm{c}\right){\mathrm{C}}_5{\mathrm{H}}_{10}$
Fill your correct answer as a, b or c.

Which of the following hydrocarbons is unsaturated?

(a) Propyne; (b) Ethane