“Set of Questions” “Practice Questions” “Exam Preparation Questions” “Questionnaire”

The carbon dioxide gas
17. Soaps and
(produced) turns limeCH,COONa + H,O +
Detergents: Soaps
such as stearic acid, palmitic are sodium and
water milky. CO,
Detergents are generally acid, etC. potassium salts of long chain
bromides ions, etc. sodium salts of ochlo (higher) fatty acids
sulphonic acids or ammonium salts
with chlorides or
NCERT INTEXT QUESTIONS
Q. 1. What would be the electron
dot structure of
carbon dioxide which has
the formula CO?
Ans. In carbon dioxide molecule, 2dbalet
the [CBSE 2019 (31/2/2)]
by double bonds. Thus, there aretwo2
Oxygen atoms are bonded on
either side with carbon atom
Carbon shares its two electrons double bonds in CO,.
in
udghanother two electrons with another the formation of a double bond with one oxygen atom and
olcarbon atom acquire the stable electronicoxygen atom. In this process,both
the oxygen atoms and the
CO, molecule is shown below: configuration of the noble gas neon. The
formation of

c*+2;0: (:o¢)c 30: or ba OECZOJ boiontOD
Valencies of C and O are 4 and 2
respecuveydis
0.2. What would be the electron dot structure of a o
molecule of sulphur which is made up of eight
atoms of sulphur? [CBSE 2019 (31/2/2)]
10 [Hint: The eight atoms of sulphur are
joined together in the form of a ring]curboxylic acid
Ans. The eight atoms of sulphur are joined together in the form of a ring. keftervesose
otol docsnot ogacarbonate
S.
S S
:S::s:
Sdoge(
S:


Aaiotae.
23. How many structural isomers can you draw for pentane?

Ans. The five carbon atoms in pentane, C;Hj can be arranged in three different ways to give three
structural isomers:
HH H

H H H H H
8 H HH HH H
H-C-C-C-C-H H-C-C-C-H
H-C-C-C-C-C-H
HC H w (
iosh H C H H
H H H H H
H H H l HH H
neopentane

n-pentane
ether e isopentane




Compounds 117
Carbon and its

, Q. 4. What are the two properties of carbon which lead to the huge number of carbon
we see around us? compounds
[CBSE 2019 (31221
Ans. () Catenation: Carbon has the unique ability to form bonds with other atoms of carbon,
property is called catenation. These compounds
rise to large molecules. This may
have gwing
chainsof carbon,branched chainsof carbon or even carbon atoms arranged in rings long




S03siot adi Straight chain Branched chain Ring

In addition, carbon atoms may be linked by single, double or triple bonds.
(ii) Tetravalency: Since carbon has a valency of four, it is capable of bonding with four otk
atoms of carbon or atoms of some other monovalent elements. In order to satisf
bnkaois tetravalency, carbon can form double or triple bonds with other C-atoms or with oxve
sdt bns erco nitrogen also. Compounds of carbon are formed with oxygen, hydrogen, nitrogen, sulbhur
lo nounIC chlorine and many other elements giving rise to compounds with specific properties which
Wdepend on the elements other than carbon present in the molecule.
Q.5. What willbe the formula and electron dot structure of cyclopentane?
Ans. The molecular formula of cyclopentane is GçH10: Five carbon atoms of cyclopentane are
connected by single bonds in a cyclic form. Following are the structural formula and electron
dot structure of cyclopentane.lethanec acid (5 o

H H
T(RSueeios aaO) H H H X
Hoamtol
CHXC Cx H n t
clsipo H HSue

H H Hx C CH
H
H H
Structural formula
Electron dot structure
of cyclopentane (C,HËo) of cyclopentane (CHËo)
Q. 6. Draw the structures for the following compounds:
(i) Ethanoic acid
(ii) Bromopentane
(iüi) Butanone S9nog 7ot w(iv) Hexanal oar lroiorH USwoi
Are structural isomers possible for bromopentane?toq ntzOIS
OcD lh
Ans. (i) Ethanoic acid
() Bromopentane
H O H H H H H
H OH C- Br
H
O 9 0 HH
haoatb o H HH
(iiü)) Butanone HH H(iv) Hexanal
H O H H
H H H H H H
H-C-C
H H H
H H H H H
Yes, structural isomers are possible for
bromopentane.
118 Xam idea Science-X