MULTIPLE CHOICE QUESTIONS
1.
Pentane has the molecular formula
C5H12. It has
(a) 5 covalent
bonds
(b)
12 covalent bonds
(c) 16 covalent
bonds
(d)
17 covalent bonds
2. Identify the unsaturated compounds from the following
(i) Propane
(ii) Propene (iii)
Propyne (iv) Chloropropane
(a)
(i) and (ii)
(b) (ii) and
(iv)
(c) (iii) and
(iv)
(d) (ii) and (iii)
3. In which of the following
compounds, — OH is the functional group?
(a) Butanone
(b)
Butanol
(c) Butanoic acid
(d)
Butanal
4.
The hetero atoms present in CH3-CH2-O-CH2-CH2-Cl are
(i) oxygen
(ii) carbon (iii) hydrogen (iv) chlorine
(a)
(i) and (ii)
(b)
(ii) and (iii)
(c) (iii) and
(iv)
(d)
(i) and (iv)
5.
Oils on treating with hydrogen in the presence
of palladium or nickel
catalyst forms fats. This is an example of
(a) addition reaction
(b)
substitution reaction
(c) displacement reaction
(d)
oxidation reaction
6. The carbon exist in the atmosphere in the form of
(a) Carbon monoxide
only
(b)
Carbon monoxide in traces and carbon dioxide
(c) carbon dioxide
only
(d)
coal
7. Buckminsterfullerene is an allotropic form of
(a) phosphorus
(b)
sulphur
(c) carbon
(d)
tin
8. The functional group present in propanal is-
(a)
-OH
(b)
-COOH
(c) -CO-
(d) -CHO
9. When vegetable oil is treated with hydrogen in the presence of nickel Or (Palladium) as a catalyst, it forms vegetable ghee. This process shows
(a) Anodising reaction
(b) Substitution reaction
(c) Displacement reaction
(d)
Addition reaction
10. The number of structural isomers for alkane
with a molecular weight 72 is
(a) 2
(b) 3
(c) 4
(d) 5
11. Which of the following is incorrectly matched?
(a) Vinegar → carboxylic acid
(b) C2H6 → alkane
(c)
Ethanol → alcohol
(d)
Methanol → ketone
13 While cooking, if bottom
of the vessel is getting
blackened on the outside,
it means that
(a) The food is not cooked properly
(b)
The fuel is not burning
properly
(c) The fuel is
wet
(d)
The fuel is burning completely
14. The chemical reaction shows the addition
of chlorine gas to hydrocarbon in the presence of sunlight.
CHCl3 + Cl2 → CCl4 + HCl
How does chlorine
react to a hydrocarbon compound
in the presence of sunlight?
(a) it adds hydrogen into the compound
(b)
it adds an oxygen atom into the compound
(c)
it substitutes hydrogen
atom from the compound
(d)
it breaks double and triple
bonds into a single bond
15. A carbon compound contains
two atoms of carbon. Which
name should the carbon
compound bear?
(a) Butane
(b)
Ethane
(c) Methane
(d)
Propane
16. The electronic configuration of an element
is found to be 2, 4. How many
bonds can one carbon atom form in a compound?
(a) 1
(b) 2
(c) 4
(d) 6
CASE STUDY BASED QUESTIONS
1. The compounds
which have the same molecular
formula but differ from
each other in physical or chemical properties are called isomers and the
phenomenon is called
isomerism. When the isomerism is due to difference in the arrangement of atoms within the
molecule, without any reference to
space, the phenomenon is called structural isomerism. In other
words.
Structural isomers are compounds that have the same molecular formula but different
structural formulas, i.e., they are different in the order in which different
atoms are linked. In these compounds, carbon atoms can be linked together in
the form of straight chains, branched chains or even rings.
i.
Which of the following
sets of compounds have the same molecular formula?
(a) Butane and iso-butane
(b) Cyclohexane and hexene
(c)
Propanal and propanone
(d)
All of these
ii.
In order to form branching, an organic compound
must have a minimum of carbon atoms
(a) 2
(b) 3
(c) 4
(d) 5
iii. Which of the following is an isomeric
pair?
(a) Ethane and propane
(b)
Ethane and ethene
(c) Propane and butane
(d)
Butane and 2-methylpropane
iv. Among the following
the one having longest chain is
(a) neo-pentane
(b)
iso-pentane
(c) 2-methylpentane
(d) 2,2-dimethylbutane
v. The number of isomers of pentane is
(a) 2
(b) 3
(c) 4
(d) 5
2. Nisha observed
that the bottoms
of cooking utensils
were turning black
in colour while the flame of her stove was yellow in colour. Her
daughter
suggested cleaning the air holes of the stove to get a clean, blue flame. She also told her mother that this would prevent the fuel from getting wasted.
i. Identify the reasons behind the sooty flame arising from the stove.
ii. Can you distinguish between saturated and unsaturated compounds by burning them? Justify your answer.
iii. Why do you think the colour of the flame turns blue once the air holes of the stove are cleaned?
2. Food,
clothes, medicines, books, or many of the things are all based on this
versatile element carbon.
In addition, all living structures are carbon based.
The earth’s crust has only 0.02% carbon in the form of minerals. The
element carbon occurs in different forms in nature with widely varying physical
properties. Both diamond and graphite are formed by carbon atoms, the
difference lies in the manner in which the carbon atoms
are bonded to one
another. Carbon has the unique ability to form bonds with other atoms of
carbon, giving rise to large molecules. This property is called catenation.
i.
From the given alternatives, whose chemical and physical properties are not same?
(a) Graphite and Diamond
(b) Phosphorous and Sulphur
(c)
Carbon and Hydrogen
(d)
Methyl alcohol and Acetic acid
ii. Which of the following statements is not correct?
(a)
Graphite is much less dense than diamond
(b)
Graphite is black and soft
(c) Graphite has low melting
point
(d)
Graphite feels smooth and slippery
iii. Which of the following are isomers?
(a)
Butane and isobutene
(b)
Ethane and ethene
(c) Propane and propyne
(d)
Butane and isobutane
iv. Which one of the following is not an allotrope of carbon?
(a) Soot
(b)
Graphite
(a) Diamond
(b) Carborundum
v.
Pentane has the molecular formula
C5H12. It has
(a) 5 covalent
bonds
(b)
12 covalent bonds
(c) 16 covalent
bonds
(d) 17 covalent
bonds
ASSERTION AND REASON QUESTIONS
DIRECTION: Each of these questions contains an Assertion
followed by Reason. Read them carefully and answer the question on the basis of following
options. You have to select the one that best describes the two
statements.
(a)
Both A and R are true and R is the correct
explanation of A.
(b)
Both A and R are true but R is not the correct explanation of A.
(c)
A is true but R is false.
(d)
A is false but R is true.
1. Assertion (A): Carbon is the only element that can form large number
of compounds.
Reason (R): Carbon is tetravalent and shows the property of catenation.
Ans. A is false but R is true.
2. Assertion (A): Diamond and graphite are allotropes of carbon.
Reason (R): Some elements can have several
different structural forms while in the same physical state. These
differing forms are called allotropes.
Ans. Both A and R are true and R is the correct
explanation of A.
3. Assertion (A): In alkanes,
alkenes and alkynes
the valency of carbon is always
four.
Reason (R): All hydrocarbons except alkanes contain
double bonds.
Ans. (c) A is true but R is false.
1. Assertion (A): The functional group present
in alcohols is – OH.
Reason (R): It is the same group as present
in water, hence
water and alcohol have similar properties.
Ans. (c) A is true but R is false.
2. Assertion (A): Carbon monoxide
is extremely poisonous
in nature.
Reason (R): Carbon monoxide
is formed by complete combustion of carbon.
Ans. (c) A is true but R is false.