All Class Assessment Grade 8 Chemistry 21-22
All Class Assessment Grade 8 Chemistry 21-22
Class Assessment
1.
What is this symbol '⇌' used to represent?
A.
dual side reaction
B.
dual side process
C. reversible reaction
D.
reversible process
2. When the system
A + B C
+ D is at equilibrium,
(a) the forward reaction has stopped.
(b) both the forward and the reverse reactions have
stopped.
(c) the reverse reaction has stopped.
(d) neither the forward nor the reverse
reaction has stopped.
3.
Meaning of the word
"anhydrous" is
A.
with water
B. without water
C.
with copper
D.
without copper
4.
A reaction in which liquid
freezes and its solid form changes into liquid at same temperature, is called
E.
dual side reaction
F.
dual side process
G. reversible reaction
H.
reversible process
5.
The
water melts and freezes at
A.
different
temperatures
B.
different
pressure
C. same temperature
D.
same
pressure
6.
Phenolphthalein change color in.
A. Acids
B. Alaklis
C. Water
7.
Dye which change color over a
specific pH range is.
A. Acids base
indicator
B. Reactant
C. Product
8.
Equilibrium can
be attained only from one side.
a) true
b) false
9.
Equilibrium of a
reaction depends on the concentration of reactants.
a) true
b) false
10.
In which of the following conditions do you think the rates of both forward and
backward reactions are the same?
a) unstable equilibrium
b) not in an equilibrium
c) the beginning of a reaction
d)
equilibrium
11.
Dynamic equilibrium mainly concerns about _______________
a)
spontaneous reactions
b) nonspontaneous reactions
c)
reversible reactions
d) Irreversible reactions
12. Dynamic equilibrium is not like a balancing see-saw.
a) true
b) false
13. The position of equilibrium of a reversible reaction can
be altered by changing the reaction conditions.
a) true
b) false
14. The effect
of temperature on equilibrium has to do with the ----------- of reaction.
a) pressure
b) heat
c) concentration
15. If the
volume of a system increases, or the ---------------- decreases, the production
of additional moles of gas will be favored.
a) pressure
b) heat
c) concentration
16. Strong acids split up (dissociate) almost completely in water.
a) true
b) false
17. An acid is
a substance that donates protons or accepts a pair of valence electrons to form
a bond.
a) true
b) false
18. Base as a
------------------------- acceptor.
a) electron
b) proton
c) both
19. Acid as a
-------------------- donor.
a) electron
b) proton
c) both
1. Positively charged ions
are called cations.
a) true
b) false
2.
Ions are formed by the addition of electrons to, or the
removal of electrons from, neutral atoms or molecules or other ions.
a) true
b) false
3.
Outermost
shell is known as the -------------.
a) electron
b) valence shell
c) both
4. Most of the elements need eight
electrons in their outermost shell in order to be stable, and this rule is
known as the -----------------.
a) electron
b) proton
c) octet rule
5. Positively charged ions
are called cations.
a) true
b) false
6.
Ions are formed by the addition of electrons to, or the
removal of electrons from, neutral atoms or molecules or other ions.
a) true
b) false
7. When
negatively charged atom is attracted towards positively charged atom and
vice-versa, it is known as -----------------------------.
a) electron
b) electrostatic attraction
c) both
8. --------------is
a type of linkage formed from the electrostatic attraction between oppositely
charged ions in a chemical compound.
a) Ionic bond
b) proton
c) octet rule
9.
The magnesium atom loses 1 electron when it reacts.
a) true
b) false
10.
Ionic compounds are neutral.
a) true
b) false
11.
An oxygen atom has
--------------------- electrons in its outer shell.
a) 4
b) 6
c) 8
12.
Magnesium is in Group
---------------------------- of the Periodic Table.
a)
2
b) 3
c) 4
13.
The structure of an ionic compound depends on the relative sizes of
the cations.
a) true
b) false
14. Ionic
compounds are usually formed when metals react with non-metals.
a)
True
b)
false
15. Ionic compounds are solids and are hard to break.
a) true
b) false
16. Ionic compounds have low melting and boiling points.
a) true
b) false
17. Ionic compounds are generally soluble in polar solvents.
a) true
b) false
18. Ionic compounds conduct electricity in the solid-state.
a) true
b) false
19.
Water molecules pull the sodium and chloride
ions apart, breaking the ionic bond that held them together.
a) true
b) false
20.
Large molecules in which the atoms are held together by ionic bonds.
a) true
b) false
21.
Giant ionic structures have -------------------------- melting points.
a) low
b) high
c) medium
22.
A big structure formed by
countless ions called-------------------.
a) giant
b) atom
c) cell
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