HSC/I/03 Student's Copy
2 0 1 8
Pre-CBCS
1st Semester
HOME SCIENCE
Chemistry
Full Marks 55
Time 2½ hours
PART A—OBJECTIVE
Marks 20
The figures in the margin indicate full marks for the questions
SECTION—A
Marks 5
Tick the correct answer in the brackets provided 1×5=5
1. The valency of phosphorus in PCl3 is
1
2
3
0
2. In organic compound, carbon is
always present
nearly always present
commonly present
rarely present
/197 1 Contd.
3. Vapours of which of the following acids are suffocating and cause damage
to the lungs?
Formic acid
Acetic acid
Oxalic acid
Citric acid
4. Ethyl alcohol is also known as
rectified spirit
power alcohol
wood alcohol
grain alcohol
5. The acid which is most abundant in lemon fruit is
acetic acid
oxalic acid
citric acid
tartaric acid
SECTION—B
Marks 15
Answer/Write on the following in not more than 5 sentences each 3×5=15
1. Oxidation and reduction
2. Write the structural formula of citric acid.
3. Write the uses of tartaric acid.
4. Define diffusion.
5. Normality
HSC/I/03/197 2 Contd.
PART B—DESCRIPTIVE
Marks 35
The figures in the margin indicate full marks for the questions
UNIT—I
1. Define the following 1×4=4
Atom
Chemical equation
pH
Molecule
An organic substance on analysis is found to have the following
percentage composition
Carbon 20·04%
Hydrogen 6·6%
Oxygen 26·67%
Find the empirical formula. 3
OR
Differentiate between oxidizing agent and reducing agent with
examples.
Calculate the amount of H2SO4 required to prepare 0·1 N in 250 ml. 3
UNIT—II
2. Differentiate between saturated and unsaturated hydrocarbons giving
examples. 2
Describe the laboratory method for the preparation of methane along
with diagram. 3
Write two tests to detect the presence of nitrogen in an organic
compound. 2
HSC/I/03/197 3 Contd.
OR
Mention the physical properties and uses of ethane. 3
Write two tests to detect the presence of oxygen in an organic
compound. 2
Write the general formula of alkene. 2
UNIT—III
3. What are alkyl halides? Write one method for the preparation of methyl
iodide.
Write the physical properties of ethyl iodide. 3
OR
What is alcohol? Write one important method for the preparation of
ethyl alcohol.
Write the physical properties and uses of methyl alcohol. 3
UNIT—IV
4. Describe the laboratory method for the preparation of formaldehyde
along with diagram. 4
Write three important uses of formaldehyde. 3
OR
What is acetone? Describe the laboratory preparation of acetone.
Mention three important uses of acetone. 3
UNIT—V
5. What is carboxylic acid? Describe one method for the preparation of
acetic acid with equation.
Write the physical properties of oxalic acid. 2
List the important uses of formic acid. 2
OR
How will you prepare tartaric acid from grape juice? 4
Write the physical properties and uses of citric acid. 3