D. A.V.
INSTITUTIONS, WEST BENGAL ZONE
HOLIDAY HOMEWORK
CLASS- XI SUB-CHEMISTRY
Q.No. Questions Marks
1 Which of the following sets of compounds correctly illustrates the law of 1
reciprocal proportions?
A
(a) P2O3,PH3,H2O
(b) P2O5,PH3,H2O
(c) N2O5,NH3,H2O
(d) N2O,NH3,H2O
2) The oxides of nitrogen contain 63.65%, 46.69% and 30.46% of nitrogen 1
by weight, respectively. This data illustrates the law of:
(a) constant proportions
(b) multiple proportions
(c) reciprocal proportions
(d) conservation of mass
3) Which one of the following will have the largest number of atoms? 1
(a) 1 gm Au (s)
(b) 1 gm Na (s)
(c) 1 gm Li (s)
(d) 1 gm cl2
Each of these questions contains two statements, Assertion and
Reason. Each of these questions also has four alternative choices,
only one of which is the correct answer. You have to select one of the
codes (a), (b), (c) and (d) given below.
(a) Assertion is correct, reason is correct; reason is a correct
explanation for assertion.
(b) Assertion is correct, reason is correct; reason is not a correct
explanation for assertion
(c) Assertion is correct, reason is incorrect
(d) Assertion is incorrect, reason is correct.
.
4) Assertion: One atomic mass unit is defined as one twelfth of the mass 1
of one carbon – 12 atoms.
Reason: Carbon-12 isotope is the most abundant isotope of carbon and
has been chosen as standard.
5) Assertion: Significant figures for 0.200 are 3 whereas for 200 it is 1. 1
Reason: Zero at the end or right of a number are significant provided
they are not on the right side of the decimal point.
6) Assertion: Both 32 g of SO2 and 8g of CH4 have same number of 1
molecules
Reason: Equal moles of substances have equal number of molecules.
7) a) Round off the following to 3 digit:- 2
(i) 2.4 + 9.389 (ii)
b) The mass of copper metal is 6.342 gm and density of copper is 7.6 gm/cm3.
What is its volume
8) a) What will be the value of multiples of the following prefixes 2
(i) micro (ii) femto
b) Calculate the mass of one carbon atom.
9) Elements X and Y form two different compounds. In the first, 0.324g of X is 2
combined with 0.741 g of Y. In the second, 0.117 g of X is combined with
0.059 g of Y. Show that these data illustrate the law of Multiple proportions.
10) a) Which one of the following will have the largest number of atoms? 1
(i) 1 gm Au (s) (ii) 1 gm Na (s) (iii) 1 gm Li (s) (iv) 1 gm cl2
b) The average atomic mass of copper is 63.5. It exists as two isotopes which 2
are 29Cu65. Calculate the percentage of each isotope present in it.
11) a) Calculate gm-mol number and amount of ammonia in 100 L ammonia gas. ½+½=1
b) 3.4 % by mass Sulphur is present in Insulin. What will be the minimum 2
molecular weight?
c) Calculate number of electron present in one drop H2SO4 (100% pure) of 2
mass 2.45X10-3.
12) Gay Lussac discovered gas laws for measuring the properties of gases (1+1+1+1=4)
along with Charles and Boyle. Gay-Lussac’s law tells about the
relationship between pressure and temperature of a gas. It talks about the
pressure-temperature relationship of the gas. According to Gay-Lussac’s
law, the pressure of a fixed amount of gas, at constant volume, is directly
proportional to the temperature. We can see in our daily lives that the
pressure of a tyre increases during summers and needs to be adjusted to
avoid bursting, whereas, in winters, the pressure decreases considerably.
1). In a closed flask of 5 litres, 1.0 g of H2 is heated from 300 to 600 K.
Which of the following statement is incorrect?
2). According to Gay-Lussac’s law for an ideal gas, the absolute pressure
of a fixed amount of gas varies directly as ________.
3). What would be the pressure of a closed gaseous system, when the
temperature is doubled?
4). If the pressure of a certain amount of gas is increased by 2 times, at a
fixed temperature, then its final volume will become ________.
