Chemistry, asked by qatar95731, 5 months ago

IDEAL INDIAN SCHOOL, DOHA-QATAR
CLASS-IX-CHEMISTRY- PRACTICE PAPER
1. Write down the formula of :
a) Sodium oxide
b) Aluminium chloride
c) Sodiumsulphide
d) Magnesium hydroxide
e) Magnesium chloride
f) Calcium oxide
g) Copper nitrate
h) Aluminium chloride
i) Calcium carbonate

2. Define the atomic mass unit.
3. Write down the names of compounds represented by the following formulae:
a) Al₂(SO₄)₃
b) CaCl₂
c) K₂SO₄
d) KNO₃
e) CaCO₃
4. How many atoms are present in a
i) H2S molecule and
ii) PO43-Ion?
5. Calculate the molecular mass of H₂, O₂, Cl₂, CO₂, CH₄, C₂H₆, C₂H₄, NH₃, CH₃OH.
6. Calculate the formula unit masses of ZnO, Na₂O, K₂CO₃, given atomic masses of Zn = 65 u, Na = 23 u, K = 39 u, C= 12 u, and O = 16 u.
7. What are polyatomic ions? Give examples
8. Give the names of the elements present in the following compounds.
a) Quick lime
b) Hydrogen bromide
c) Baking powder
d) Potassium sulphate
9. Give the names of the elements present in the following compounds.
e) Quick lime
f) Hydrogen bromide
g) Baking powder
h) Potassium sulphate
10. Separation techniques with diagrams
Chromatography
Separating funnel
11. Calculate the number of moles for the following:
i) 72 g of C (finding mole from mass) ii) 18.066x 1023 number of C atoms.
12. State law of constant proportion.
13. Which process can purify the impure sample of potash alum?
14. Name the solutions which show the Tyndall effects
15. What is centrifugation? Explain briefly.
16. Name some homogenous as well as heterogeneous mixtures.
17. What are the differences between a physical change and a chemical change?
18. What is the procedure to obtain different gases from air?
19. How is fog different from smoke?
20. How to separate two immiscible liquids?
21. What is water called a universal solution?
22. How can you prove that water is a compound?
23. What is the difference between fog and smoke?
24. Show the different types of colloids with examples.
25. What is Tyndall effect?

Multiple choice questions
26. The atomicity of K2Cr2O7 is
I. 9
II. 11
III. 10
IV. 12
27. The formula for quicklime is
I. CaCl2
II. CaCo3
III. Ca(OH)2
IV. CaO
28. The symbol of cadmium is
I. Ca
II. Cu
III. Cm
IV. Cd
29. All noble gas molecules are
I. Monoatomic
II. Diatomic
III. Triatomic
IV. Both I and II
30. The valency of nitrogen in NH3 is
I. 1
II. 3
III. 4
IV. 5
31. The formula of ethanol is C2H5 OH. What will be its molecular mass?
I. 46 u
II. 34 u
III. 34 g
IV. 46 g
32. Number of moles present in 28g of nitrogen atoms are
I. 1 mole
II. 2.3 moles
III. 0.5 mole
IV. 2 moles
33. The molecular mass of x is 106. x can be
I. CaCo3
II. So3
III. Na2Co3
IV. NaCl
34. Which among the following is not a postulate of Dalton’s atomic theory?
I. Atoms cannot be created or destroyed
II. Atoms of different elements have different sizes, masses and chemical properties
III. Atoms of same elements can combine in only one ratio to produce more than any one compound
IV. Atoms are very tiny particles which cannot be further divided
35. Which of the following is a wrong Combination?
I. 6.022 X 1023 molecules of oxygen = 32g of oxygen
II. 6.022 X 1023 ions of sodium = 23g of sodium
III. 6.022 X1023atoms of C = 24g of carbon
IV. 6.022 X1023 atoms of H = 1g of hydrogen atoms

Assertion - Reason type questions

(I) Both A and R are true and R is correct explanation of the assertion.
(II) (ii) Both A and R are true but R is not the correct explanation of the assertion.
(III) (iii) A is true but R is false.
(IV) (iv) A is false but R is true.
1. Assertion (A): Boiling is a bulk phenomenon.
Reason (R): It takes place at room temperature.
2. Assertion (A): In gaseous state particles move randomly in high speed.
Reason (R): The particles of gases have least forces of attraction

Answers

Answered by pmanorma1973

Answer:

Explanation:

ANSWER

i) Sodium oxide : Na

ii) Aluminium Chloride : AlCl

iii) Sodium sulfide : Na

iv) Magnesium Hydroxide : Mg(OH)

The chemical formula of Given compounds are :

(a) Magnesium chloride

(b) Calcium oxide

(d) Aluminium chloride

(e) Calcium carbonate

Answered by sanjudnath

hope its helpful!!!!!!!!!!!!

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