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Solved Chemistry Notes And MCQs FOR ECAT MCAT
Fundamental Concepts in Chemistry
Q.
1. The soul of chemistry is its dealing
with
Internal
structural changes in matter
Composition
of matter
Properties
of matter
Composition
and properties of matter
(d)
Q.
2. All of the following statements are
incorrect for 20 mol of hydrogen peroxide except
it
has 20 mol of hydrogen atoms
it
has 30 mol of oxygen atoms
it
has 80 mol of atoms
30
mol of hydrogen atoms
(c)
Q.
3. If proton number of two atoms is
same then it can be concluded that
they
are isotopes
compounds
of both with CI2 will be similar in reactivity towards other
compounds
both
have same colors
both
have same melting points
(b)
Q.
4. A chemist poured lemon juice on
soil, the idea that he may have in his mind is that
there
may be a possibility of a chemical reaction
lemon
juice is dangerous to health
lemon
juice is dangerous to health
water
should be preferred over lemon juice for drinking
(a)
Q.
5. Dr. Khan has discovered two isotopes
of an element with atomic number 119. The relative abundance of isotopes 119Uue300
and 119Uue305 is 70% and 30% respectively. The average
atomic weight of Uue is
301.5
a.m.u
302.5
a.m.u
303.5
a.m.u
304.5
a.m.u
(a)
Q.
6. Which of the following is not
related to a.m.u
gram
kilogram
microgram
gram/lit
(d)
Q.
7. The number of significant figures in
0.00200 is
two
three
five
one
(b)
Q.
8. All of the following statements are
incorrect except
precision
and accuracy should go side by side in a scientific work
scientific
work must be precise, accuracy is not essential
scientific
work must be accurate, precision is not essential
+calculations
must be made before any experiment
(a)
Q.
9. Empirical formula and formula unit
of an ionic compound
are
always similar
are
always different
may
be similar or different
ionic
compounds don’t’ have any empirical formula
(c)
Q.
10. Copper (II) oxide is mixed with
organic compound during combustion analysis. The purpose is
to
carry out complete combustion
to
reduce the economy of the process
to
reduce the time for completion of the reaction
all
of the above
(a)
Q.
11. Bismark brown is a dye. Its molar
mass is 228.3 g/mol. When the dye was analyzed by a scientist, it was found
that it contains 30.68% nitrogen. How many nitrogen atoms are there in each
Bismark brown molecule?
6
5
4
3
(b)
Q.12. The mass of 2 mole of sodium hydroxide will
be
2
g
20
g
40
g
80
g
(d)
Q.
13. “A” compound is always consists of
the same elements combined in the same fixed ratio”. The statement is
a
hypothesis
a
fact
a
law
an
observation
(c)
Q.
14. Compound having highest boiling point
among the following is
HF(I)
HCI(I)
HBR(I)
HI(I)
(d)
Q.
15. Islamian genius investigated that the
amount of heat required to raise the temperature of 11 gram of water form 30oC
to 31oC is
one
calorie
little
bit greater than on calorie
little
bit less than one calorie
never
equal to one calorie
(c)
Q.
16. An atom is
smallest
indivisible particle in an element
smallest
particle of an element which can undergo a chemical reaction
building
block of an element
always
smaller than molecule
(b)
Q.
17. 10 moles of H2O contains
100
moles of bonds
100
moles of electrons
30
atoms
25
moles of hydrogen bonds
(b)
Q.
18. The volume of one kilogram of water
at 4oC is equal to one litre. The temperature of water is kept at 4oC
because water
has
no dissolved gasses at this temperature
has
maximum density at this temperature
polarity
of water molecule is least at this temperature
dipole
moment has maximum value at this temperature
(b)
Q.
19. A compound contains two elements X
and Y percentage of X is 20% (At.wt = 40) and that of Y is 80% (At.wt =80). The
empirical formula of the compound is
XY2
X2Y
X3Y
XY
(A)
Q.
20. A piece of paper is burnt in air, the
gas produced is passed through distilled water. The PH of water solution will
be
1
7
2.1
6.8
(d)
Q.
21. Which of the following is a
substance?
sea
water
brass
tape
water
graphite
(d)
Q.
22. Freezing point of a substance is a
temperature at which a liquid substance is converted to solid, it is
always
lower than its melting point
usually
a little lower than its melting point
always
higher than its melting point
exactly
the same as its melting point
(d)
Q.
23. Number of covalent bonds in 10 mol of
carbon tetrachloride is
2.4
x 1025
40
4
x 1024
6.4
x 1021
(a)
Q.
24. A student subtracted 0.00055 from
10.2345678 and reported the result as 10.23401. But his friend told him that
the result was wrong. What is the correct result?
10.234017
10.2340178
10.234
10.23
(d)
Q.
25. The following statement contained in
a student’s laboratory report is a conclusion.
a
gas is liberated
colour
of the gas is greenish yellow
oxide
of the gas is strongly acidic
the
gas is chlorine
(d)
Q.
26. If 10g each of uranium and hydrogen are converted into energy
according to equation E = mc2
energy
obtained from uranium will be too much greater than that of hydrogen
energy
obtained from hydrogen will be a little bit less than that of uranium
energy
obtained from hydrogen and uranium will always be exactly equal
diamond
(c)
Q.
27. A student analyzed a sample of sea
water and found that it contained 2.3g of NaCi, 0.005g of MgSo4,
0.234g of CaCI2 and 60.12g of H2O. Total mass of the
sample is
62.659
62.65
62.70
65.7
(d)
Q.
28. A 50.00 mL sample of a cough mixture
prepared by a pharmacist was found to have a mass of 46.0g. what is the density
(in g/mL) of this mixture. Stated to the correct number of significant figures?
0.92
0.920
0.9200
1.087
(b)
Q.
29. Ozone (O3) filters the
cosmic rays of sunlight. How many oxygen atoms are there in 0.2 mole of ozone
(O3, molar mass 48.0 g/mol)?
6.02
x 1022
6.02
x 1023
3.61
x 1023
6
x 1023
(c)
Q.
30. On heating, the hydrated salt CaSO4,
xH2O loses its water of crystallization. In an experiment it was
found that when 0.2 mol of the hydrated salt was heated 0.10 mol of water was
lost. What is the molecular formula of the hydrated compound?
CaSO4
CaSO3.
½ H2O
CaSO4.H2O
CaSO4.2H2O
(b)
Q.
31. Zirconium chloride reacts with
magnesium to produce Zirconium. The process is called Knoll process.
ZrCI4 + 2Mg Zr + 2MgCI2
How
many moles Zr would be produced if 0.2 mol of Mg metal is used in the reaction?
0.1
0.01
0.20
0.05
(a)
Q.
32. Tobacco contains a poisonous alkaloid
called Nicotine. The molecular formula of nicotine is C10H14N2
(molar mass = 162.23g). The mass percentage of nitrogen in nicotine, is?
4.32%
8.23%
12.4%
17.3%
(d)
Q.
33. A sample of an ionic compound
contains 2.82 g Na, 4.35 g CI, and 7.83 g O. The empirical formula of this
compound is:
NaCIO2
NaCIO3
NaCIO
NaCIO4
(d)
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