Download Mongar Higher Secondary School

Mongar Higher Secondary School
Monger: Bhutan
Mid-term examination -2010
Time:11/2hrs
Marks:80
Sub: Chemistry
Class:X
Section A
(Compulsory : To be attempted by all the candidates.)
Question 1
Directions: Each question in this part is followed by FOUR possible choices of
answer. Choose the correct answer and write it in the separate answer sheet
provided.
[15]
i)
An acid which is monobasic.
a) H2SO4
b) H3PO4
c) H2SO3
d) HCl
ii)
a)
b)
c)
d)
The tendency of an element in a molecule to attract the electrons towards
itself
Electron Affinity
Ionization Potential
Electronegativity
Valency.
a)
b)
c)
d)
The crystalline substances which on exposure to air loses water of
crystallization either wholly or partially are called
hygroscopic substances
deliquescent substances
efflorescent substances
desiccating agent
iii)
 The chemical reaction given below is to be used with question iv.
2H 2 ( g )  O2 g   2H 2 O g 
iv)
In the above reaction, the volume of hydrogen that will combine with 30
litres of oxygen to form steam is
a) 60 litres
b) 50 litres
c) 40 litres
d) 30 litres
Class X Bio.
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MHSS. Mid-Term Exam-2010
v)
a)
b)
c)
d)
An acid which is present in the stings of ants and bees
Tartaric acid
Acetic acid
Formic acid
Oxalic acid
a)
b)
c)
d)
The modern periodic law is based on
Atomic weight
Atomic size
Atomic number
Atomic radius
vi)
vii)
a)
b)
c)
d)
A polar covalent compound
H2
O2
NaCl
H2O
viii)
a)
b)
c)
d)
Base which is used in making of soap
Ca(OH)2
Mg(OH)2
NaOH
NH4OH
ix)
a)
b)
c)
d)
When a metal atom becomes an ion
it loses electrons and is oxidized
it gains electrons and is reduced
it gains electrons and is oxidized
it loses electrons and is reduced.
a)
b)
c)
d)
Compound X simply consists of molecules. The type of bonding in X will
be
Ionic
Electrovalent
Covalent
Coordinate.
x)
Class X Bio.
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MHSS. Mid-Term Exam-2010
 The table given below is to be used with question X
Solutions
A
B
C
D
xi)
a)
b)
c)
d)
xii)
a)
b)
c)
d)
PH
values
6
14
7
1
In the table given above, which solution has the maximum H+ ions?
Solution with PH value 6
Solution with PH value 14
Solution with PH value 1
Solution with PH value 7
The chemical properties of an element depend on the
electronic configuration
number of valence electrons
number of shells
number of electrons.
xiii) In what ratio will hydrogen combine with oxygen to form hydrogen
chloride in the following equation
H 2  Cl2  2HCl
a)
b)
c)
d)
1:1:1
1:2:1
1:1:2
2:2:1
xiv)
a)
b)
c)
d)
The common name of hydrated Ferrous Sulphate is
green vitriol
blue vitriol
white vitriol
yellow vitriol
xv)
a)
b)
c)
d)
an atom and a cation will have
the same number of protons
the same number of neutrons
different number of protons
different number of neutrons.
Class X Bio.
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MHSS. Mid-Term Exam-2010
i)
Match each item under column A with the most appropriate item in
Column B
Column A
1) Magnesium hydroxide
2) Avogadro’s number
3) Periods
4) Atomic number
5) Acetic acid
Column B
a) 6.023x1023
b) vertical columns
c) antacid tablet.
d) horizontal rows
e) 6.023x1023
f) soap
g) protons
h) monobasic acid
ii)
Fill in the blanks by choosing words from the list given below.
[5]
( empirical formula, salt, ionization, cation, molecular formula, base, acid, anion,
dissociation, mercury, oxygen, sodium)
i)
A base reacts with an acid to form a …………and water only.
ii)
Negatively charged ion is called……….
iii) ………….is a chemical formula which gives the simple whole number
of different types of atoms present in a molecule of compound.
iv) The metal which occurs in liquid form is………..
v)
The process by which covalent compounds are converted to ions in
aqueous solution is called………….
iii)
Name the following
[5]
i)
The salt formed by the complete replacement of ionisable hydrogen
atoms of an acid by metal or ammonium ion.
ii)
The amount of substance containing particles equal to Avogadro’s
number.
iii) According to electronic concept, a process in which one or more
electrons are lost.
iv) The fundamental property used for classification of elements in the
modern periodic table.
v)
A salt which is used in some kind of ‘iron tablets’ which people use to
cure anaemia.
iv)
What weight of carbon dioxide is formed by the complete combustion of 6
grams of carbon in the following equation?
[2]
(At. Wt. ;C=12, O=16)
C  O2  CO2
Class X Bio.
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MHSS. Mid-Term Exam-2010
v)
Give at least two differences between electrovalent compounds and
covalent compounds with one example each.
vi) Give reasons for the following.
i)
Table salt (NaCl) becomes moist and sticky during rainy season.
ii)
Alkalis should not be left exposed to air
iii) Ionic compounds are bad conductors in solid state but are good
conductiors in molten state or in their aqueous solutions.
iv) The atomic size decreases across the period.
v)
Sodium chloride solution is neutral.
[3]
[5]
Section B (40 marks)
Attempt any four questions.
Question 2
a) Define the following
i)
Avogadro’s law
ii)
Basicity of acid
iii) Periodicity
[3]
b) A part of the periodic table, sharing the position of same elements as given
below.
1)
2)
3)
4)
1
2
3 Li
4
5
6C 7N
80
9
10
11Na 12 13 14 15P 16S 17 18
some of the boxes in the periodic table above contain a number
a) What is this number called?
[1]
b) Which element should be there in the box having the number 17?
[1]
What is the name given to vertical columns of the periodic table?
[1]
Write the electronic configuration of Na
[1]
What is the common feature of the electronic configurations’ of the elements
in the same group?
[1]
c) Find out the total percentage of oxygen in MgSO4.7H2O.
(Mg=24, S=32, H=1, O=16)
Question 3
a) Complete the following statements.
i)
The size of a sodium atom is………than that of chlorine atom
ii)
The volume occupied by 1 mole of gas at STP is……..
iii) The total number of atoms in one molecule of H2O…….
iv) The only non-metal which occurs in liquid state is…….
Class X Bio.
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MHSS. Mid-Term Exam-2010
[2]
[4]
b) Calculate the number of cations and anions present in one mole of ferric
chloride. (FeCl3)
[2]
c)
i)
What should be the nature of the substance applied on the stings of
wasps? What types of reaction take place?
[2]
ii)
What is the volume occupied by 8g of sulphur dioxide?
[2]
( At.Wt:- S=32, O=16)
Question 4
a)
i)
Distinguish between Acid –Base indicators and Universal indicator [2]
ii)
The empirical formula of a compound is C2H5. It has a vapour density
of 29. Determine the relative molecular mass of the compound and
hence its molecular formula.
[3]
b) An atom X is in second period and group II A of the periodic table.
i)
What is the number of valence electrons in its atom?
[1]
ii)
What will be the formula of the compound formed by X with chlorine?
iii)
[1]
Is it a metal or non-metal?
[1]
c)
i)
ii)
Acids dissolve in water to produce positively charged ions. Draw the
structure of these positive ions.
[1]
What type of bond is present in sodium chloride, NaCl?
[1]
Question 5
a) Lhatu found that the blue copper sulphate crystals when kept open in air
turned white.
i)
What is the reason for this change?
[1]
ii)
State the nature of salt?
[1]
b)
i)
Define the term molecular formula.
ii)
Chlorofluoro carbons (CFC’s) are the compounds that contain only
carbon, Chlorine and fluorine.
A particular CFC has the following composition.
C = 8.7% , F = 13.8% , Cl= 77.5%
Calculate the empirical formula of the compound.
( At.Wt= C= 12, F=19, Cl= 35.5)
[3]
Class X Bio.
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MHSS. Mid-Term Exam-2010
c)
i)
ii)
iii)
Question 6
a)
i)
ii)
iii)
b)
i)
ii)
State Gay-Lussac’s law.
[1]
What volume of oxygen would be required to burn completely 150ml of
carbon monoxide? Calculate the volume of carbon dioxide formed in
the reaction
[2]
2CO+O2 → 2CO2
How many moles of hydrogen chloride can be produced from 1 mole of
hydrogen and one mole of chlorine?
[1]
Define ionization potential.
What happens to metallic character down the group?
How many horizontal rows are there in a periodic table?
[1]
[1]
[1]
Give one difference between acid salt and normal salt with one example
each.
[2]
Comment on the statement, “all alkalis are base but all bases are not
alkalis”
[1]
c)
i)
ii)
Define relative atomic mass
[1]
1.55g of sodium peroxide reacts with water according to the following
equation.
2Na2O2 + 2H2O→ 4NaOH + O2
Calculate
1) Weight of sodium hydroxide formed.
2) Volume of oxygen liberated at STP
3) Weight of oxygen liberated.
[1]
[1]
[1]
All the best
Class X Bio.
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MHSS. Mid-Term Exam-2010