Enfant India International School: Chemistry

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Saturday, 10 July 2021

Enfant India International School Std 12 Ist Unit Test Marks : 40 Subject : Chemistry

July 10, 2021 Chemistry, Class 12, Ist Unit Test, Question Paper

Attempt all questions :

1. Fill in the blanks :

(a) Two liquids are partially miscible when the intermolecular attraction of one liquid is _____ from that of the other .

(b) The ppm of a solute is defined as the mass of solute (in grams ) present in _____ grams of solution .

(d) For a non ideal solution showing positive deviation from Raoult's law , ∆Hmixing is _______ .

(e) ∆Tf = Kf × ______ .

2. Answer the following questions :

(a) Define the terms : molarity , molality and normality .

(b) Define vapour pressure of a liquid. What is the effect on vapour pressure when a non - volatile solute is added to it ?

(d) Define Raoult's law .

(e) Explain the difference between osmosis and diffusion .

(f) What do you understand by relative

lowering of vapour pressure ? How is it measured ?

3. An aqueous solution of a non volatile

and non electrolytic substance boils at

Enfant India International School Std 7 Ist Unit Test Marks : 40 Subject : Chemistry

July 09, 2021 Chemistry, Class 7, Ist Unit Test, Question Paper

Enfant India International School Std 6 Ist Unit Test Marks : 40 Subject : Chemistry

July 09, 2021 Chemistry, Class 6, Ist Unit Test, Question Paper

Enfant India International School Std 10 Ist Unit Test Marks:40 Subject: Chemistry

July 09, 2021 Chemistry, Class 10, Ist Unit Test, Question Paper

Attempt all questions :--- (1×5=5)

1. M is an element in the form of a powder .M burns in oxygen and product obtained is soluble in water .The solution is tested with litmus.Write down only the word which will correctly complete each of the following sentences.

(a) If M is a metal, then the litmus will turn _________ .

(b) If M is a non metal , then the litmus will turn _______ .

(d) If M is a metal ,it will form ______ oxide , which will form _______ solution with water .

(e) If M is a non metal , it will not conduct electricity in the form of _______ .

2. Give one example in each case :

(1×5=5)

(a) A basic oxide which is soluble in water .

(b) A hydroxide which is highly soluble in water .

(d) A base which is not an alkali

(e) An oxide which is a base

3. Define : (2×3=6)

(a) A chemical bond

(b) An electrovalent bond

4. What are the conditions for the

formation of an electrovalent bond ? (3)

5. Draw electron dot diagram and structure

of :. (2×3=6)

(a) Nitrogen molecule

(b) Magnesium chloride

6. Define a coordinate bond and give the condition for its formation . (5)

7. Explain the following methods with

examples. (2×5=10)

(a) Direct combination

(b) Displacement

(d) Neutralisation of insoluble base

(e) Neutralisation of an alkali

Enfant India International School Std 9 Ist Unit Test Marks:40 Subject : Chemistry

July 09, 2021 Chemistry, Class 9, Ist Unit Test, Question Paper

Sub. -– Chemistry

Attempt all questions :––

1. Fill in the blank (1×5=5)

(a) The chemical change involving iron and HCl illustrate a _______ reaction.

(b) In the type of reaction called ______ two compounds exchange their positive and negative radicals .

(d) Formula of iron(3) carbonate is ________ .

(e) Symbolic expression for a molecule is called ______.

2. Complete and balance the following reactions :. ( 2×5=10)

(a) NaCl(aq) + AgNO3 (aq) ––-->

(b) Pb(NO3 )2 + KI ---–>

∆

(d) Pb(NO3)2 –----------->

(e) NH3 +O3 ––---------->

3. Define the following: (2×5=10)

(a) Photochemical reaction

(b) Electrochemical reaction

(d) Exothermic reaction

(e) Decomposition reaction

4. What do you understand by chemical.

reaction ? (3)

5.State the main characteristics of chemical

reactions . Give at least one example in

each case . (3)

6. What do you understand by hydrolysis ?

Explain giving examples . (3)

7. Find the percentage mass of water in the

Epsom salt MgSO4 . 7H2O . (3)

8. Explain the terms valency and variable

valency . (3)

Enfant India International School Std 8 Ist Unit Test Marks: 40 Subject : Chemistry

July 09, 2021 Chemistry, Class 8, Ist Unit Test, Question Paper

Std 6 Chemistry Unit test II

February 11, 2021 Chemistry, Std 6, Unit test II

Unit II ( 2020-21 )

Std- VISubject- ChemistryM:M-20

Q1-Write true or false against each statement:5m

i. Nitrogen gas makes up about71% of the air.

ii. Soil contains air.

iii. Burning of coal causes air pollution.

iv. All fuels burn in the presence of carbon dioxide.

v. River water is as saline as sea water.

Q2-Fill in the blanks with the suitable words- 5m

i. The thick layer of air surrounding the earth is called…………….

ii. ……………….gas present in the air is used to make fertilizers.

iii. The oxygen present in the air is used for……………..

iv. Plant lose water from their leaves by the process of………….

v. The water that is fit for drinking is called ………………..

Q3-Choose the correct option- 5m

i. Which gas present in air is used by plants for making food throughphotosynthesis?

a. Carbon dioxide b. Oxygen

ii. Which gas present in the air do not support burning?

a. oxygen b. Nitrogen

iii. Which of these is not a waterborne disease?

a. Diarrhoea b. Malaria

iv. Flood causes great damage to

a. Humans only. b. Human and animals both

v. The process of seeping water into the ground is called-

a. Aquiferb. Infiltration

Q4- Give one word for the following- 5m

i. The percentage of this gas in the air is 21% .__________

ii. The process by which oxygen gas is released in the air.________

iii. A substance which burns in the presence of air to give out heat and light.________

iv. Rain with acid dissolved in it._____________

v. Unwanted and harmful substances that contaminate water._______

Std 8 Chemistry Unit test II

February 11, 2021 Chemistry, Std 8, Unit test II

Enfant India International school

Class -8th

Sub.- Chemistry M.M.-20

Section -A

1. Fill in the blanks:. (1×5=5)

(a) The symbol of aluminum is __________ .

(b) The valency of nitrogen is _________ .

(d) The short form of an element is called _________.

(e) Carbon dioxide has atom of carbon and ______ atoms of oxygen.

2. Write the molecular formula of. (1×5=5)

(a) Cuprous oxide

(b) Calcium oxide

(d) Iron sulphide

(e) Ammonium hydroxide

Section -B

3. Define the following:. (1×5=5)

(a) Oxides

(b) Neutral oxides

(d) Reducing agent

(e) Chemical reaction

4. Answer these questions:. (1×5=5)

(a) Define chemical reaction.

(b) What is a redox reaction ? Explain

With the help of an example.

( C) What is meant by symbol ?

(d) Calculate the valency of sulphur and chlorine.

(e) State law of conservation of mass .

Std 7 Chemistry Unit test II

February 11, 2021 Chemistry, Std 7, Unit test II

Unit II ( 2020-21 )

Std- VII Subject- Chemistry M:M-20

Q1-Write true or false against each statement:5m

i. Sodium metal is stored under water.

ii. Bromine is the only liquid metal.

iii. Oxygen gas is used to preserve food.

iv. The reactants are written on the left hand side of the reaction.

v. Formation of a precipitate is indicated by an upward arrow.

Q2-Fill in the blanks with the suitable words- 5m

i. In the preparation of ammonia, iron is used as…………….......

ii. Diamond is a form of……………..

iii. Metals make a……………. sound on being struck.

iv. Water break down into its constituents hydrogen and……….

v. Metallic oxides are generally…………….. in nature.

Q3-Choose the correct option- 5m

i. Which of these is the most ductile metal?

a. Sodium b. Gold

ii. Which of the following substance is brittle?

a. Sulphur b. Copper

iii. A chemical reaction is-

a. Temporary b.Permanent

iv. The formula of sodium chloride is-

a. NaClb. HCl

v. A metal which violently reacts with water-

a. Sodiumb. Aluminum

Q4- Give one word for the following- 5m

i. A homogeneous mixture of two or more metals and nonmetals ._____

ii. Ability to be hammered into thin sheets.________

iii. A new substance formed in a chemical reaction.________

iv. Ability to be drawn into thin wires.___________

v. When metal tracts with oxygen it forms.__________

Std 7 Chemistry First Semester 2020

December 21, 2020 Chemistry, Question Paper, Std 7

Enfant India International School

Semester I 2020-21

Std- VII Subject- Chemistry M:M-40

Section I ( 20 marks )

Q1-Write true or false against each statement: 5m

i. Digestion of food is a physical change.

ii. A compound is a pure substance.

iii. Carbon dioxide is an element.

iv. The symbol of Carbon is C.

v. Nucleus is negatively charged.

Q2-Fill in the blanks with the suitable words- 5m

i- The substance taking part in chemical reaction is called……………

ii- Water breaks down into its constituents hydrogen and…………….

iii- A chloride ion has one unit…………… charge.

iv- Sugar solution is a………..…. mixture.

v- Photosynthesis is a………..…. change.

Q3-Choose the correct option- 5m

i- Elements present in carbonate ion are-

a. Carbon and oxygen b. Carbon and hydrogen

ii- The number of valence electrons in magnesium atom is-

a. 2 b. 1

iii- The molecular formula of water is-

a. H₂O b. N₂O

iv- The symbol of sodium is-

a. N b. Na

v- An example of chemical change is-

a. Cutting of wood b. Burning of wood

Q4- Give one word for the following- 5m

i. The process in which solid directly changes into a gas.___________

ii. Unreactive gases which are present in traces in air._____________

iii. Small dense and positively charged central core of an atom.______

iv. The substance formed in the chemical reaction._____________

v. These are written on the left-hand side of the reaction.__________

Section II ( 20 marks )

Q5- Define any three of the following terms- 2X3= 6m

i. Atomic number

ii. Radical

iii. Electronic configuration

iv. Atom

v. Mass number

Q6- Differentiate between the following- 2X2= 4m

i. Reactants and products

ii. Compound and mixtures

Q7- Give reasons for the following- 2X2= 4m

i- Why do we need to classify elements.

ii- Why elements are called pure substances.

Q8- Answer the following questions- 2X3= 6m

i- What is a chemical reaction?

ii- Give the symbols of the following-

A. Sulphur

B. Phosphorus

C. Calcium

D. Chlorine

iii- Give the valencies of the following radicals-

A. Carbonate

B. Sulphate

Std 6 Chemistry First Semester 2020

December 19, 2020 Chemistry, Question Paper, Std 6

Enfant India International School

Semester I 2020-21

Std- VI Subject- Chemistry Marks-40

Section I ( 20 marks )

Q1-Write true or false against each statement: 5m

i. Common salt is an element.

ii. The symbol of nitrogen is N.

iii. Melting of ice is a chemical change.

iv. Chalk powder can be separated from water by filtration.

v. Solids can flow easily.

Q2-Fill in the blanks with the suitable words- 5m

i- Burning of a substance is a……….. change.

ii- Salt can be obtained from sea water by..…….. .

iii- …………can be compressed to some extent.

iv- ………....is a metal which is liquid at room temperature.

v- Most physical changes are…………….. .

Q3-Choose the correct option- 5m

i- Pure substances are classified as-

a. Elements b. Elements and compounds

ii- Which is a liquid metal?

a. Iron b. Mercury

iii- The liquid that passes through the filter paper is called-

a. Residue b. Filtrate

iv- The amount of space occupied by an object is called-

a. Volume b. Material

v- The molecules are very closely packed in-

a. Solids b. Liquids

Q4- Give one word for the following- 5m

i. The short form used to represent the name of an element.__________

ii. A positively charged particle present in the nucleus of atom.________

iii. A negatively charged particle present in the shell of an atom.________

iv. The liquid that dissolves a solid in it._____________

v. Anything that occupies space and has mass._____________

Section II ( 20 marks )

Q5- Define any three of the following terms- 2X3= 6m

i. Melting point

ii. Fusion

iii. Condensation

iv. Atom

v. Molecule

Q6- Differentiate between the following- 2X2= 4m

i. Chemical change and physical change

ii. Mixture and compound

Q7- Give reasons for the following- 2X2= 4m

i- Filtration is a better method of separating an insoluble solid component as compared to decantation.

ii- A chair is considered as solid.

Q8- Answer the following questions- 2X3= 6m

i- How can matter be classified on the basis of chemical constitution?

ii- What do you understand by an alloy?

iii- Name the elements present in

A. Sodium chloride ( NaCl )

B. Calcium oxide ( CaO )

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