Basic concept of chemistry (class XI) Chemistry

Class: XI                                                                   Subject: Chemistry

Total Marks: 15                                                       Chapter:1

Choose correct options:

1.         9 grams of water decompose to give                                                   (1)

 1g hydrogen and 8g oxygen

 8g oxygen and 1g hydrogen

 4g oxygen and 16g hydrogen

 2g hydrogen and 1g oxygen

2.         100 g of CaCO₃ on heating gave 44 g of CO₂ and 56 g of CaO. The observation is in agreement with the:                                                                  (1)

 Law of conservation of mass

 Law of constant proportion

 Law of multiple proportion

 Law of reciprocal proportion

3.         In carbon dioxide ratio of mass of carbon to mass of oxygen is always 3:8 . This is in accordance with:                                                                   (1)

 Law of conservation of mass

 Law of constant proportion

 Law of multiple proportion

 Law of reciprocal proportion,

4.         The atomic masses and chemical properties of Sulphur and phosphorus are different this can be explained on the basis of                              (1)

 Law of constant proportions

 Law of conservation of mass

 Dalton's Atomic theory

 Laws of Chemical combination

5.         Hydrogen and oxygen combine in the ratio 1:8 by mass to form water. How much mass of oxygen gas would be required to react completely with 3 g of hydrogen gas?                                                                                        (1)

 8 g

 16 g

 24 g

 32 g

6.         Dalton's atomic theory provided explanation for                                 (1)

 Law of conservation of mass

 Law of definite proportions

 Both law of conservation of mass and law of definite proportions

 Atomic numbers

7.         Which postulate of Dalton's Atomic Theory can explain the law of Definite Proportion                                                                                              (1)

 All matter is made of very tiny particles called atoms

 Atoms of a given element are identical in mass and chemical properties.

 Atoms combine in ratio of small whole numbers to form compounds

 The relative number and kinds of atoms are constant in a given compound.

8.         What is percentage composition of oxygen in NO^3-                                                          (1)

9.         Calculate the molar mass of Ca (NO₃)₂.                                                (1)

10.        How many moles are in 26.9g of C₁₁H₁₂O₁₁.                                          (1)

11.        Find the percentage composition of KMnO₄.                                       (2)

12.        A compound has a percentage composition of 46.681% Nitrogen and 53.32 % Oxygen. It’s molecular mass is 59.98 amu. What is the empirical formula? What is it’s molecular formula?                                                                                       (3)

Molecular Mass Calculations (Chemistry)

Class: XI                                                                      Subject: Chemistry

1.                  Calculate the molecular mass of the following compounds

(a)    CuSO₄.5H₂O

(b)   K₂Cr₂O₇

(c)    Pb₃(PO₄)₂

(d)   NaNH₄HPO₄.4H₂O

(e)    FeSO₄(NH₄)2SO₄.6H₂O

ELECTRONIC CONFIGURATION SCHEME

Test on law of chemical combinations (Chemistry) Class : XI

Answer the following questions:

Choose correct options

1. A balanced chemical equation is in accordance with:

a. Avogadro’s law

b. Law of conservation of mass

c. Law of gaseous volumes

d. All of the laws above.

2.  Which one of the following pair of substances illustrates law of multiple proportions?

a. Calcium oxide and calcium hydroxide

b. Sodium chloride and sodium bromide

c. Carbon monoxide and carbon dioxide

d. None of these

3 The percentage of copper and oxygen in samples of “CuO” obtained by different methods were found to be the same. This illustrates the law of:

a. Constant proportion

b. Conservation of mass

c. Multiple proportions

d. Reciprocal proportion

Match the following:

Column A

1. Law of conservation of mass
2. Law of definite proportions
3. Law of multiple proportions
4. Law of reciprocal proportions
5. Law of combining volumes

Column B 

1. Joseph Proust
2. Antoine Lavoisier
3. Richter
4. Gay lussac
5. Dalton

Answers:

1 b

2 c

3 a

Match

1 vs 2

2 vs 1

3 vs 5

4 vs 3

5 vs 4

TEST ON UNITS AND DIMENSIONS (CLASS: XI)

TEST: UNITS AND DIMENSIONS               MARKS: 10

Write dimensional formulas of the following physical quantities.

1.                  Momentum

2.                  Power

3.                  Energy

4.                  Pressure

5.                  Stress

6.                  Frequency

7.                  Temperature

8.                  Acceleration due to gravitation

9.                  Weight

10.              Density                                                       

Sample test paper (Chapter: Control and Coordination) Biology Class X Board CBSE

Chapter: Control and Coordination                                      TOTAL MARKS: 19

CLASS: X                                                                          TIME: 30min

Board: CBSE                                                                      SUBJECT: BIOLOGY

1. Define reflux. (1)

2. Draw structure of neuron. (2)

3. Explain geotropism in plants. (2)

4. Name some involuntary actions of our body. (2)

5. Give examples of hydrotropism and chemotropism in plants. (2)

6. How do auxins promote the growth of a tendril around a support? (2)

7. Why it is important to have iodized salt in our diet? (2)

8. Why there is change in our appearance as we approach 10-12 years of age? (2)

9. How is our body sugar level controlled naturally? (2)

10. Draw structure of human brain. (2)

Sample Test Paper CHAPTER Acid, Base and Salt (CBSE) Class X

CHAPTER: ACID BASE AND SALT                         TOTAL MARKS: 20

CLASS: X                                                                               TIME: 30min

Board: CBSE

1. Write chemical formula of baking soda? (1)

2. Why common salt becomes sticky during rainy season? (1)

3. Give formula of two acids which are monobasic. (1)

4. An aqueous solution with pH zero is________ (acidic/basic/neutral/amphoteric). (1)

5. What name is given to the water in the compound Copper sulphate-5-water? (1)

6. How bee stings are treated at home? (1)

7. Explain why? Blue vitriol change to white upon heating. (1)

8. Which has higher pH.? A concentrated or dilute solution of HCL? (1)

9. How will you show that acetic acid is monobasic acid (1)

10. Why? Anhydrous calcium chloride is used in desiccators? (1)

11. Why does not an acid show any acidic behavior is the absence of water? (2)

12. Why alkalis like sodium hydroxide and potassium hydroxide should not be left

exposed to air? (2)

   13. Write following

(i) Define an acid.

(ii) What is an alkali?

(iii) Explain the meaning of the term acid salt? (3)

14. What will you observe when:

(i) Red litmus is introduced into a solution of sodium sulphate.

(ii)Methyl orange is added to dil HCl.

(iii)Blue litmus is introduced into a solution of ferric chloride. (3)

SAMPLE QUESTION PAPER (PHYSICS) X (CBSE) FORCE

CLASS: X                                                                   Time: 45min

Chapter: FORCE                                                         Marks: 26

Subject: Physics

1. What is restoring force? (1)

2. Define Law of Inertia. (1)

3. Write C.G.S units of force. (1)

4. Define Dynamic Equilibrium. (1)

5. Write general characters of Non-Contact forces. (2)

6. Write examples of Contact forces. (2)

7. State Second Law of motion. (2)

8. Define the term Linear Momentum. State its SI units. (2)

9. How much acceleration will be produced in a body of mass 10kg acted upon by a force of 2kgf. (2)

10. A body of mass 1.5kg is dropped from a height of 12m. What is the force acting on it during its fall? (2)

11. The momentum of a force of 5N about a point P is 2Nm. Calculate the distance of point of application of the force from the point P. (2)

12. On a see saw, two children of masses 30kg and 50 kg are sitting on one side of it at distances 2m and 2.5m respectively from the middle. Where should a man of mass 74kg should sit to balance it? (2)

13. A body is acted upon by two forces each of magnitude F, but in opposite directions. State the effect of the force if.

(a)    both forces act at the same point of the body.

(b)   two forces act at two different points of the body at a separation r. (2)

14. A spanner (or wrench) has a long handle. Why? (2)

15. What do you understand by the term couple? State its effect. Give two examples of couple action in our daily life. (2)

Sample question paper (CBSE Board Exam) Class X Subject : Biology

TEST : Biology                                    LIFE PROCESSES (SCIENCE)

CBSE Board                                         CLASS: X

Total Marks: 20                                  Time: 30min

1. What are the raw materials of photosynthesis? (1)

2. How many chambers Human heart posses? (1)

3. What is the role of nephrons? (1)

4. What is the role of saliva in digestion? (1)

5. Which unit of kidney does filtration process? (1)

6. Differentiate between transport of materials in xylem & phloem (2)

7. What is the function of diaphragm? (2)

8. Why the blood group of donor and receiver must match? (2)

9. Why the blood groups of donors and receiver person should be same for the transfusion of blood? (2)

10. Explain the nutrition in amoeba with the help of diagram? (2)

11. State two vital functions of kidney? (2)

12. Give detailed structure of chloroplast? (3)

SOLUTIONS BOARD EXAMINATION PAPERS FREE (X, XII) CHEMISTRY PHYSICS BIOLOGY (CBSE, ISC, WB, PSEB)

Dear students

I provide solutions to the board exam questions.
It is absolutely free.
Please leave questions in comments to get the solutions.
Thanks.

Research papers/Manuscript (Spectroscopic analysis/ sugar technology/Applied chemical sciences)http://works.bepress.com/aamarpali/

This is the link where you can find my research papers.

http://works.bepress.com/aamarpali/

Physics (Electricity) Xth CBSE

PHYSICS (ELECTRICITY)                                                CLASS: X

BOARD: CBSE                                                                  TIME ALLOWED: 45MIN

1. A metallic conductor has loosely bound electrons called free electrons. What is the charge on the metallic conductor?                                                                 1

2. Define the term volt.                                                                                        1

3. State Ohm’s law                                                                                               1

4.   How many electrons are there in 2C charge                                             1

4. Why electrical appliances have fuse wire?                                                  2

5. Heating element of an electric iron is made of which metal. Give reason too?

2

6. Alloys are used in electrical heating devices rather than pure metals. Give reason.                                                                                         2

7. Two metallic wires A and B are connected in second wire A has length l and radius r, while wire B has length 2l and radius 2r.

Find the ratio of total Resistance of series combination and the resistance of wire A, if both the wires are of same material?                                                         2

8. Calculate the resistance of an electric bulb which allows a 20A current when

connected to a 440V power source?                                                          2

9. A house hold uses the following electric appliance;

(i)                Refrigerator of rating 400w for ten hour each day.

(ii)              Two electric fans of rating 80w each for twelve hours each day.

(iii)            Six bulb of rating 18w each for 6hours each day.

Calculate the electricity bill of the household for the month of June if the cost

per unit of electric energy is Rs. 5.00                                                         3

10. Draw a schematic diagram of a circuit consisting of 10V battery, 5 ohm, 3W and1Wresistor, an ammeter and a plug key, all connected in series.

                                                                                                                                    3

chemistry test (periodic table) Xth ICSE Board

CHEMISTRY TEST (PERIODIC TABLE)

CLASS: X                                                                         BOARD: ICSE

1. Fill in the blanks.

a)      There are ------- groups in periodic table.

b)      Group 2 elements are called ----- metals. .

c)      Group 17 elements are called -------- family.

d)      ------- period is the shortest period.

e)      The electronic configuration of Cl is -----.

2. Chose from the options and fill in the blank.

a)      Moving across a ___________ (group, period) of the Periodic Table, the elements show increasing ___________ character. (metallic, non-metallic).

b)      The element below sodium in the same group would be expected to have a ______ (lower/higher) electro-negativity than sodium and the element above chlorine would be expected to have a _________ (lower/higher) ionization potential than chlorine. 

c)      On moving from left to right in a given period, the number of shells -------- (remains the same/increases/decreases)? 

d)      On moving down a group, the number of valence electrons ------------- (remains the same/increases/decreases)?

e)      Moving across a ___________ (group, period) of the Periodic Table, the elements show increasing ___________ character. (metallic, non-metallic).

f)        The ionization potential------------- (increases, decreases) on going down a Group.

g)      The atomic size of elements ------------------ on moving from left to right in a period (increases, decreases)

3. With reference to the variation of properties in the Periodic Table, which of the following is generally true?

.
a) Electron affinity increases going down a group.
b) Electro negativity increases going down a group.

4. Define valency?

5. How many elements are in the second period?

6. Why are elements at the extreme left and extreme right the most reactive?

Biology, Chemistry, Physics Teacher Kolkata Dr Aamarpali Roy

Biology, Chemistry, Physics Teacher Kolkata Dr Aamarpali Roy

Test Physical quantities 11th physics

[PHYSICAL QUANTITIES , MEASUREMENT DIMENSIONS]

Test questions : Physics  11^th class

1. Filling the blanks:

(i)                  3.0m/s² = ______Km/hr²

(ii)                6.67 x 10^-11 Nm²/Kg² = __________g^-1cm³s^-2

2. Write SI units of thermodynamic temperature, electric current, amount of substance and luminous intensity.

3. Two resistance

 R₁ = 200 + 4 Ω

 R₂ = 300 + 6 Ω

are connected in series. Then what is the equivalent resistance.

4. If velocity, time and force were chosen E=mv² the basic quantities, find the dimensions of mass.

5. The velocity v of wave depend on their wavelength λ density of water ρ and the acceleration due to gravity g. Find relation between these quantities by the method of dimension?

6. The force acting on an object of mass (m) traveling at velocity (v) in a circle of radius (r) is given by

F=mv²/r

            The measurements recorded as m [m= 3.5Kg + 0.1Kg]

            v = 20m/s + 1m/s

            r = 12.5m + 0.5m

            Find the maximum possible

(i)                  fractional error

(ii)                % error in the measurement of force

(iii)               What is the recorded reading

7. What is the difference between A⁰ and AU?

8. Give two methods for measuring time intervals?

9. E , m, l and G denote energy, mass, angular momentum and gravitational constant respectively. Determine the dimensions of El²/m⁵G²

10. State which of the following are dimensionally correct

(i)                  Pressure = Energy per unit volume

(ii)                Pressure = momentum x volume x time

11. The density of cylindrical rod was measured by

ρ =4m/ ПD²l

            The percentage error in m, D, l are 1%, 1.% and 0.5%. Calculate % error in the

 calculated value of density.

class 10 CBSE (Chemical reactions and equations

Total Marks: 20                                                                                    Class : X

(Chapter: Chemical reactions and Equations)

1. The reaction H₂ + Cl₂             2HCl

 (a) Oxidation                                       (c) Decomposition

 (b) Reduction                                      (d) Combination

2. When dil HCl is added to Zinc pieces taken in a test tube

  (a) no change takes place

  (b) H₂ gas bubble appear

  (c) pungent gas evolved

  (d) it turns milky

3. Heat is evolved during which reaction

   (a) endothermic reaction                    (c) combination reaction

   (b) exothermic reaction                    (d) displacement reaction

4. Why food particles are packed in aluminum foil?

5. Identify the substance oxidized and reduced in the following reaction

     CuO(s) + Zn(s)             ZnO (s) + Cu(s)

6. Why is combustion reaction an oxidation reaction?

7. Identify the type of reaction in the following

   (a) A                 B + C              (b) AB + CD               AD + CB

8. In the reaction  

         MnO₂ + 4HCl                 MnCl₂ + 2H₂O + Cl₂ 

(a)    Name the substance oxidized

(b)   Name the oxidizing agent

(c)    Name the reducing agent and the substance reduced

9. Write the balanced equation for the following

(a) Potassium bromide (aq) + Barium iodide (aq)                  Potassium iodide (aq) + 

                                                                                                 Barium bromide (aq)

 (b) Zinc carbonate (s)                 Zinc oxide (s) Carbon dioxide (g)

 (c) Hydrogen (g) + Chlorine (g)                Hydrogen chloride

10. Balance the equation:

    (a) HNO₃ + Ca(OH)₂                 Ca(NO)₂ + H₂O

    (b) NaCl + AgNO₃                 AgCl + NaNO₃

    (c) BaCl₂ + H₂SO₄                 BaSO₄ + HCl

test periodic table

Test : Periodic Table

Questions

1. Define valency. [1]

2. How does valency vary in a group and period in the periodic table? [1]

3. What is the valency of noble gases? [1]

4. How do metals react in a period? [1]

5. How do metals react in a group? [1]

6. How does the reactivity of non–metals changes in a period and group? [2]

7. Give the properties of the oxides in a particular period. [2]

8. What is an amphoteric oxide? [1]

9. Define a neutral oxide. [1]

10. Why does lithium form covalent bond unlike other alkali which forms ionic

bond?

11. What is the general outer electronic configuration of f – block elements? [1]

12. Why do Na and K have similar properties? [1]

13. Arrange the following elements in the increasing order of metallic character :

Si, Be, Mg, Na, P. [1]

14. The atomic number of an element is 16. Determine its position in accordance

to its electronic configuration. [2]

15. Why are elements at the extreme left and extreme right the most reactive? [2]

16. Why does the ionization enthalpy gradually decreases in a group? [1]

17. Why does electronegativity value increases across a period and decreases

down period? [2]

18. How does electronegativity and non – metallic character related to each

other? [2]

link to my tutor profile

http://tutorindia.net/Tutor_Profiles-OTcwMw-Dr_Aamarpali_Roy

Class XI (Chemistry) Organic chemistry test

Test (Hydrocarbons)

1. Define the term homologous series.                                                                   (1)

2.  What are saturated and unsaturated hydrocarbons?                                           (1)

3. Give IUPAC name of the following organic structure:     

 a) (CH₃)₂CHCH(C₂H₅)CH₂CH₂CH₃

            b) CH₂=C(C₂H₅)CH₂CH₂CH₃

            c) (CH₃)₂C=CHC(C₂H₅)=CH₂

            d) CH₃C≡CCH(C₂H₅)₂

            e) (CH₃)₃CC≡CCH₂CH=C(CH₃)₂                                                                         (5)

4.         Write down the products of ozonolysis of 1,2-dimethylbenzene (o-xylene).

            How does the result support Kekulé structure for benzene?                             (2)

5.           In the alkane H3C CH= CH C(CH3)2 CH2 CH(CH3)2, identify 1°,2°,3° carbon

atoms and give the number of H atoms bonded to each one of these.                (3)       

6.       Write Friedel Crafts acylation reaction?                                                                 (2)

7.         Explain  Markovnikov rule.                                                                                   (3)

8.  Write structures of the following compounds                                                             (4)

(i) 2,8-Dimethyl-3, 6-decadiene;

(ii) 1,3,5,7 Octatetraene;

(iii) 2-n-Propylpent-1-ene;

(iv) 4-Ethyl-2,6-dimethyl-dec-4-ene;

9.  Define

(a)    inductive effect, (b) electromeric effect, (c) resonance                             (5)

(d) hyper conjugation. (e) geometrical isomerism

Maths test for new students admitted to class VII

Test paper: Maths  For new student to be admitted in Class :7^th

1.                  Which of the given expressions is not an equation?
A) 7x = 6
B) 4x + 9 = 90
C) 3x > 8
D) 7x + 5 = 9

2.                  The variable in the equation 4x + 12 = 16 is x.
A) True
B) False

3.                  123.456 + 345.098 + 111.111 = ____.
A) 579.665
B) 597.665
C) 597.656
D) 579.565

4.                  23450 is not divisible by 5.
A) True
B) False

5.                  The two whole numbers occurring just before 1000 are ____.
A) 900 and 800
B) 1001 and 1002
C) 998 and 999
D) 996 and 997

6.                  The supplementary angle of 1/2 of 120⁰  is ____.
A) 130^o                                        B) 120^o
C) 60^o                                          D) 100^o

7.                  A polygon having 3 sides is called a ____.
A) pentagon                       B) rectangle
C) square                           D) triangle

8.                  In a city there are two shops which sell groceries. The sales per month of the first shop are Rs 38,000 and that of the second shop are Rs 27,000. The total annual sales of both the shops is ____.
A) Rs 78,000                     B) Rs 65,000
C) Rs 7,80,000                  D) Rs 6,50,000

9.                    is the proper arrangement of fractions in ascending order.
A) True
B) False

10.              A number is said to be exactly divisible by another number if the remainder is ____.
A) 0                       B) 1
C) 2                       D) 5

11.                can be expressed as a mixed fraction as ____.
A)  
B)  
C)  
D) 

12.              127 + (-19) + 23 + (-11) = ____.
A) -100                  B) 130
C) 120                   D) -140

13.              The cost of fencing a rectangular park of length 200 m and breadth 105 m at the rate of Rs 12 per metre is ____.
A) Rs 7320
B) Rs 7444
C) Rs 7544
D) Rs 7644

14.              The angle whose magnitude is 179^o will be a(n)____ angle.
A) obtuse                           B) reflex
C) acute                             D) complete

15.              Additive inverse of 90 is ____.
A) 90
B) -90
C) 0
D) -1

ANSWER

1.      C

2.      A

3.      A

4.      B

5.      C

6.      B

7.      D

8.      C

9.      A

10.  A

11.  C

12.  C

13.  A

14.  A

15.  B

aamarpali in this world: Laws of chemical combination

aamarpali in this world: Laws of chemical combination

Laws of chemical combination

1. Law of conservation of mass or Law of conservation of matter

Statement: Matter can neither be created nor be destroyed.


2. Law of definite proportion

Statement: When two elements combine to form a given compound, they always do so in fixed proportion.


3. Law of multiple proportion

Statement: When two elements combine to form more than one compound, the masses of one element which combine with a fixed mass of the other element are in ratios of small whole numbers.

Cheating in exams!

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What is our main motive ? to get knowledge and understanding or certificate?

Hi friends!

After many years I have started blogging again. Now I am in new phase of life. I am learning recipes other then north Indian.

I am missing my lab and my research journals no doubt but many more things but in totally new atmosphere.

I will get back to you soon!

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