Very short answer questions
(V.S.A) : X Chemical reactions and
Chemical Equation:FA
|
1.
Arrange the following metals in the decreasing under of reactivity or electro
positive character.
|
K Zn
Na Fe Pb Cu
|
2.
Which of them will be a reducing agent a metal or non metal?
|
3.
Balance the chemical equation
|
4.
Select the combination reaction from following
(i)KClO3
® KCl + 3 O2
|
5.
Select the decomposition reaction from following
(i)
2H2O + O2 ® 2H2 O
(ii)
CaCO3 ------Heat------® CaO + CO2
|
6.
Select the double displacement reaction
(i)
BaCl2 + H2SO4 ---® Ba SO4 + H2
(ii)
2KBv + Cl2 ® K Cl2 + Bv2
|
7.
Fill in the following about reactivity series of metal
(a)
the …………………. Metal replaces the ………………. Metal from its salt solution.
|
8.
Which of the following is not the necessary condition for rusting
|
(i)
Presence of oxygen (ii) Presence of catalyst (iii) Presence of moisture
|
9.
Which of the following is required for prevention of corrosion?
|
(i)
coating of less electropositive metal
|
(ii)
coating of move electropositive metal
|
10.
Choose the correct about rancidity
|
(i)
Rancidity is a reduction process (ii) Rancidity is an oxidation
process
|
Answers
|
1. K
> Na > Zn > Fe > Pb > Cu
|
2. Non
metal
|
3. 2
Na(s) +2 H2O ® 2NaOH
+ 2H2
|
4. S +
O2 ® SO2
|
5.
CaCO3 ------Heat® CaO + CO2
|
6.
BaCl2 + H2SO4 ® Ba SO4 + H2
|
7.
Strong, Weak
|
8.
Presence of catalyst
|
9.
Coating with move electropositive metal
|
10.
Rancidity is an oxidation process
|
See some
questions: Short Answer type Question (2 marks)
|
1.
(i) What happens when aqueous solution of barium chloride is added to aqueous
sodium sulphate solution?
|
(ii)
When silver coloured metal (A) is added to dilute sulphuric acid, solution
(B) is formed which is colourless solution and a gas (c) is evolved which is
colourless name ‘A’, ‘B’ and ‘C’ and write the equation?
|
(iii)
An ‘A’ blue coloured crystalline salt on heating decomposes to ‘B’ white
substance. W hen in
|
blue
salt solution, a metal (Zinc) is added, its gives rise to colourless solution
‘C’ wth leaving behind ‘D’ reddish brown metal.
|
2.
Name the compounds ‘A’, ‘B’, ‘C’ and ‘D’
|
(iv)
A reaction mixture of chromium Oxide is heated with aluminum powder on
strong heating
|
3.
a. Write the reaction?
|
b.
Give one application of this reaction?
|
(v)
Define Rusting?
|
4.
Give two methods of protection of metal trans rusting.
|
5.
(i) Rusting is a slow electrochemical process in which hydrated oxide of
metal in formed from metal when it comes in with air moisture (ii) By
Painting, by galvanization, by tinning
|
6.
(i) Explains the term ‘corrosion’?
|
(ii)
Write the chemical reaction of corrosion of Iron?
|
(iii)
Name two metals which corrodes easily?
|
(iv)
Aluminum corrodes in moist air but is widely used is making utensils.
|
(v)
what is galvanization and why do we use Zn for it?\
|
7.
(i) What is rancidity? Where does it happen
|
(ii)
what are anti oxidants? Why are they added fat and oil containing food to
prevent from rancidity?
|
(iii)
why do most items puffed with nitrogen.
|
Solution:
|
1.
White precipitate of BaSO4 is obtained. Reaction will be as
|
Na2SO4 +
BACl2 ----------------® BaSO4 + 2NaCl
|
2. A
is Zinc, B is ZnSO4 solutions C is H2gas and reactions will be
|
Zn (s)
+ H2SO4 (d) ------------® Zn SO4 (aq) + H2 (g)
|
3. A,
B, C, and D are respectively-
|
CuSO4,
5 H2O, CuSO4, ZnSO4 (aq), Cu (s)
|
4.
(i)Cr2O3 + 2Al ------® Al2O3 + 2 Cr
|
(ii)
This reaction is used in termite welding
|
5. (i)
The process of slow destruction of metals when exposed to air, moisture and
pollutant gases , in called as corrasim
|
(ii)
Fe + 3H2 + 2H2O
------------® Fe2O3 x H2O
|
(iii)
Formation of green coating on copper and formation of thin layer of oxide on
aluminum are example of corrosion.
|
(iv)
Aluminum forms oxide layer on exposure to air, this oxide layer further
checks corrosion.
|
(v)
Galvanization is a process in which Zinc layer is applied on Iron. It is used
to protect iron from rusting.
|
6. (i)
The oxidative deterioration of oils and fats leading to stinking smell or
stale taste is known as rancidity.
|
(ii)
Anti Oxidants are those chemicals which an addition to fat and oil checks it
from rancidityan addition of anti oxidants fatty food is protected from stale.
|
(iii)
Nitrogen is filled in potato chips & other food to create anaerobic (air
free atmosphere) which avoids rancidity.
|
Ratna sagar living science 6 answers by jsunil. Class6 Living science solution Term-1 Living Science Solution chapter-1 Source of food Download File Living Science Solution chapter-2 Component of food Download File Living Science Solution chapter-3 Fibre to fabric Download File Living Science Sol ch-4 Sorting of material into group Download File Living Science Soln ch-5 Separation of substance Download File Living Science Solution chapter-6 Change around Us Download File Living Science Solution ch-7 Living and Non Living Download File Living Science Solution ch-8 Getting to Know Plants Download File Living Science Sol ch-9 The Body and Its movements Download File Visit given link for full answer Class6 Living science solution Term-II
Comments
Post a Comment