Sunday, March 20, 2011

Carbon And Its Compounds MCQ's

(Q.1) The molecular formula of alcohol derived from pentane is

(a) C5H9OH
(b) C5H7OH
(c) C5H11OH
(d) C5H10OH

(Q.2) Cleansing action of soaps is based on the principle that

(a) Soap reacts with the dust
(b) The ionic end of the soap dissolves in water while the carbon chainbonds with oil or dirt.
(c) The soap molecules attracts dirt.
(d) Soap combines with the dirt.

(Q.3) Saponification is

(a) Is dehydration of the ester
(b) Is the hydrolysis of the ester
(c) Is the hydration of the ester
(d) Is the formation of ester

(Q.4) Ethanol gets oxidized to

(a) Ethanal with alkaline KMnO4.
(b) Ethanoic acid by alkaline KMnO4
(c) Ethanal in presence of cuperic oxide.
(d) Ethanoic acid in presence of platinum catalyst.

(Q.5) Esterification is the name given to

(a) Reaction of an alcohol with a carboxylic acid in presence of Sulphuric acid
(b) Formation of a new substance.
(c) A type of addition reaction.
(d) A type of rearrangement reaction.

(Q.6) Ethanol is a highly inflammable liquid implies that it is highly combustible:

(a) Ethanol catches fire at high temperatures.
(b) Ethanol burns with ayellow sootyflame
(c) The products obtained after combustion are Carbon dioxide and water.
(d) The products of combustion is an organic acid and water.

(Q.7) Substitution reactions are those reactions in which

(a) Saturated hydrocarbons replace the cations of an inorganic compound
(b) One type of atoms or a group of atoms takes the place of another.
(c) Alkyl group replaces the anion of an inorganic compound
(d) Are shown by unsaturated hydrocarbons.

(Q.8) Addition Reactions are those reactions in which-

(a) The reaction takes place immediately on mixing the reactants
(b)
Unsaturated hydrocarbons add hydrogen in presence of a catalyst.
(c)
Hydrogen atom is replaced by a group of atoms containing more than one atom.
(d)
Two molecules of the same hydrocarbon form a larger molecule.

(Q.9) Alcohols are compounds-

(a) Containing – OH group attached to alkyl group.
(b)
Containing – CO- group attached to alkyl groups.
(c)
Containing – CHO group attached to alkyl group.
(d)
Containing – COOH group attached to alkyl group.

(Q.10) Most carbon allotropes and carbon compounds on complete combustion

(a) Give a foul smell
(b) Produce a dark mass
(c) Release heat and light in addition to liberating CO2
(d) None of these

(Q.11) The two consecutive members of a homologous series differ by:

(a) CH group
(b) 14 u
(c) Functional group
(d) CH3 group

(Q.12) Which of the following functional group contains Carbon, Hydrogen and Oxygen ?

(a) Aldehyde
(b)
Amine
(c)
Nitro
(d)
Halogen

(Q.13) Homologous series is a series of compounds in which

(a) The same functional group substitutes for hydrogen in a carbon chain.
(b) Formulae of successive compounds differ by a –CH3 – unit.
(c) Representation is possible by aany formula.
(d) Is collection of compounds with different functional groups.

(Q.14) Functional group in an organic compound

(a) is an atom or group of atoms bonded to carbon in a unique manner.
(b) Present in the compound
(c) Present in the container
(d) Makes no difference to the compound.

(Q.15) Chemical properties of an organic compound (carbon compound) depend on-

(a) The functional group
(b)
Constituent elements
(c)
Number of hydrogen atoms
(d)
Number of carbon atoms

(Q.16) Occurrence of organic compounds having same molecular formula but different structures is called

(a) Catenation
(b) Allotropy
(c) Isomerism
(d) Isotopes

(Q.17) Saturated carbon compounds

(a) have the carbon atoms linked together with a single covalent bond.
(b) are normally not very reactive.
(c) are also called alkenes.
(d) Are not very useful.

(Q.18) The unique ability of a carbon atom to form bonds with other atoms of carbon is called-

(a) Catenation
(b)
Allotropy
(c)
Isomerism
(d)
Isotopes

(Q.19) Graphite is smooth & slippery and a good conductor of electricity because

(a) Each carbon atom is bonded to three other carbon atoms.
(b) One of the bonds connecting the Carbon atoms is a double bond.
(c) Bonds are strong.
(d) Carbon atom is sp hybridised.

(Q.20) Diamond is the hardest substance because-

(a) It has a rigid three-dimensional structure.
(b) It has no free electrons.
(c)
It has hexagonal layers of carbon rings over each other.
(d)
It has a two-dimensional structure.

(Q.21) Occurrence of carbon in different forms is termed as-

(a) Catenation
(b)
Allotropy
(c)
Isomerism
(d)
Isotopes

(Q.22) A covalent compound :

(a) Have definite geometry.
(b) Have strong bond.
(c) Are poor conductors of electricity and have low melting and boiling points.
(d) Are electrolytes.

(Q.23) Carbon completes its octet by-

(a) Donating the four electrons
(b)
Accepting four electrons
(c)
Sharing the four electrons
(d)
Forming ions

Friday, March 18, 2011

Science_Light_HumanEye_Test

Science – Test ( light and reflection, Human Eye) M.M:50

A. One Marks Questions. (Marks 12 )

1. Where will the image be formed when an object is placed between the
pole and focus point of the mirror?
2. A convex lens has a focal length of 50cm.What is its power?
3. An object placed at F of a convex lens will produce an image at ______
4. Mirrors used in vehicle headlights is__________Mirror
5. Dispersion of light by a glass prism takes place because of ________
6. Negative value of focal length of a spherical mirror indicates that it is______mirror.
7. Light is a form of ___________ radiation
8. A ________ image can be obtained on a screen.
9. An object placed at F of a concave mirror will produce an _________ image
10. A person is not able to see distant objects clearly, because he is suffering from _________
11. An object placed at 2F of a convex lens will produce an image ______,______
12. Lens formula is expressed as._________


B. Two Marks Questions (Marks 8 )

13. What is the cause of cataract?
14. Hypermetropia is corrected by which type of lens?
15. Why do we prefer a convex mirror as a rear-view mirror in vehicles
16. Why does the sky appear dark instead of blue to an astronaut?

C. Three Marks Questions. (Marks 15 )
17. Define refraction and reflection of light.
18. What is presbyopia? How is it corrected?
19. What is the difference between real and virtual images?
20. Find the focal length of a convex mirror where radius of curvature is 32 cm.
21. What are the uses of a concave mirror?

C. Five Marks Questions. (Marks 15 )

22. An object is placed at a distance of 10cm from a convex mirror of focal
length 15 cm. Find the position and nature of the image.
23. What is refraction of light? Write a law of refraction.
24. An object 5 cm in length is held 25 cm away from a converging lens of focal length 10cm. Draw the ray diagram and find the position, size and nature of the image formed.

Light- Reflection And Refraction MCQ

Light -Reflection and Refraction
(Q.15) Negative value of focal length of a spherical mirror indicates that it is
(a) Concave mirror(b) Convex mirror(c) Plane mirror(d) Convex mirror of small focal length

(Q.16) Light is a form of ___________ radiation
(a) Electrical (b) Mechanical (c) Longitudinal (d) Electomagnetic

(Q.17) A ________ image can be obtained on a screen.
(a) Real (b) Virtual (c) Erect (d) Inverted

(Q.18) Refraction of light can take place at the boundary of
(a) Transparent media (b) Opaque media (c) Any medium (d) Rarer medium

(Q.19) According to the laws of reflection
(a) Angle i = Angle r (b) Sine i = sine r (c) Sine i / Sine r = constant (d) tan i = tan r

(Q.20) An object placed at F of a concave mirror will produce an image
(a) At focus (b) Diminished (c) Real and Inverted (d) Virtual

(Q.21) An object placed at infinity of a concave mirror will produce an image
(a) Behind the mirror (b) Diminished (c) Virtual and erect (d) Enlarge

(Q.22) An object placed at F of a concave lens will produce an image
(a) On opposite side of the object (b) Enlarge (c) Virtual and erect(d) Real and inverted

(Q.23) An object placed at 2F of a convex lens will produce an image
(a) At 2F (b) Enlarge (c) Real and Inverted (d) Virtual
(Q.24) An object placed between F and 2F of a convex lens will produce an image

(a) Virtual (b) Diminished (c) Real and Inverted (d) Erect

(Q.25) According to the laws of refraction (Snell’s law)
(a) Angle i = Angle r (b) Sine i = sine r (c) Sine i / Sine r = constant(d) an i= tan r
(Q.26) Absolute Refractive index of a substance is

(a) Speed of light in vacuum / Speed of light in the medium
(b) Speed of light in water / Speed of light in the medium
(c) Speed of light in the medium / Speed of light in air
(d) Speed of light in medium/speed of light in water





(Q.27) According to Cartesian Sign Convention
(a) Object distance is always negative (b) Object distance is always positive
(c) Image distance is always negative (d) Image distance is always positive

(Q.28) Magnification produced by a concave mirror is
(a) Negative for a real image and Positive for a virtual image
(b) Only positive (c) It produces no magnification (d) Only negative

(Q.29) A ray of light propagates from an optically denser medium to an optically rarer medium.
(a) It will bend towards the normal after refraction.
(b) It will bend away from the normal after refraction.
(c) It will continue to go on the same path after refraction.
(d) It will refract making an angle of refraction equal to the angle of incidence.

(Q.30) Radius of curvature of a spherical mirror (or lens) is
(a) Half of its focal length (b) Double of its focal length
(c) Equal to its focal length (d) There is no relation

Q.31) The distance between a spherical lens and the image is – 15 cm. The lens is
(a) Concave lens(b) Convex lens(c) Either of the two irrespective of the object distance(d) Either Concave lens or Convex lens with object between O and F.

(Q.32) Power of a lens is
(a) Equal to its focal length (b) Reciprocal of the focal length (in meters)
(c) Square of its focal length (d) Reciprocal of its radius of curvature

(Q.33) Lens formula is expressed as
(a) 1/v - 1/u = 1/f (b) 1/v + 1/u = 1/f (c) 1/u - 1/v = 1/f (d) u + v = f

(Q.34) The colour of an object is determined by
(a) The colour of light reflected by it. (b) The colour of light absorbed by it.
(c) The colour of light incident on it only. (d) The colour of light transmitted by it.

(Q.35) The three primary colours are
(a) Red, Blue and Green (b) Red, Yellow and Blue (c) Red, White and Blue (d) Violet, Green and Red
(Q.36) Convex lenses are also called

(a) Converging lenses (b) Diverging lenses (c) Circular lenses (d) Plane lenses
Q.38) In which case the image formed by a concave mirror is of the same size as the object?
(a) When object is placed at infinity(b) When object lies at C(c) When object lies at F
(d) When object lies between C and F

Carbon And Its Compounds Worksheet 3

Carbon and its Compounds

(Q.1) Why is Diamond the hardest substance ?
(Q.2) Write the structural formula of 2-methyl propane
(Q.3)14. Structural formula of 2- propene.

(Q.4)Give the general formula of the functional group ketones, aldehyde, carboxylic acid groups
(Q.5) What is molasses?
(Q.6)Define esterfication.
(Q.7)What are Addition and substitution Reactions. Give examples?
(Q.8) How is an ester prepared in the lab? Write its one use in daily life.
(Q.9) Give the test to distinguish between saturated and unsaturated hydrocarbons.

(Q.10) What happens when sodium reacts with ethanol? Give chemical equation also?

(Q.11) What substances are added to ethanol to make it unfit for drinking purposes?

(Q.12) The two consecutive members of a homologous series differ by:
a) CH group (b) 14 u (c) Functional group (d) CH3 group
(Q.13) Define Isomerism. Show isomerism in C6H14.
(Q.14) The total number of structural isomers possible for the hydrocarbon pentane (C5H12) is
(Q.15) Give the structural formula of 2,2-dimethylpropane, isobutene

Carbon And Its Compouds Worksheet 2

Carbon and its Compounds

(Q.1) The two consecutie members of a homologous series differ by:______
(Q.2) Functional group in an organic compound________
(Q.3) Carbon completes its octet by ___________
(Q.4) How many covalent bonds are formed between two nitrogen atoms in a nitrogen molecule?
(Q.5) The total number of structural isomers possible for the hydrocarbon pentane (C5H12) is
(Q.6) The hydrocarbons having the general formula of CnH2n-2 , CnH2n+2 and CnH2n+1 –X are known as
(Q.7) The next higher homologue of pentane and propylene is
(Q.8) The IUPAC name of formaldehyde and acetaldehyde is ________and ________

(Q.9) What is meant by homologous series? State any four characteristics.
(Q.10) Alcohols are compounds-
(a) Containing – OH group attached to alkyl group.(b)Containing – CO- group attached to alkyl groups.
(c) Containing – CHO group attached to alkyl group(d Containing – COOH group attached to alkyl group.
(Q.11) Most carbon allotropes and carbon compounds on complete combustion
(a) Give a foul smell(b) Produce a dark mass (c) Release heat and light in addition to liberating CO2(d) None of these
(Q.12) The two consecutie members of a homologous series differ by:
a) CH group (b) 14 u (c) Functional group (d) CH3 group
(Q.13) Define Isomerism. Show isomerism in C6H14.
(Q.14) Differnece between isobutene and n-butane?
(Q.15) Give the structural formula of 2,2-dimethylpropane, isobutene.

Science_CarbonAndItsCompounds_Class10

(Q.1) Why is Diamond the hardest substance ?
(Q.2) Occurrence of carbon in different forms is termed as-
(Q.3) What are the saturated and unsaturated hydrocarbon?
(Q.4) How many double and single bonds are present between carbon atoms in benzene?
(Q.5) The hydrocarbons having the general formula of CnH2n-2 are known as
(Q.6) Alkynes are represented by the general formula
(Q.7) Write the molecular formula of i) alkane ii) alkene iii) alkyne having 8 carbon atoms.
(Q.8) What are Hydrocarbons? Give examples?
(Q.9) Write electron dot structure of ethane and benzene
(Q.10) Write the structural formula of 2-methyl propane
(Q.11) what is unique property of carbon?
(Q.12) Why do carbon forms compounds mainly by covalent bonding?
(Q.13) Give difference in the structure of diamond and Graphite
(Q.14) A molecule of ethane (C2H6) contains
(a) 4 covalent bonds. (b) 5 Covalent bonds. (c) 6 Covalent bonds. (d) 7 Covalent bonds.
(Q.15) Graphite is smooth & slippery and a good conductor of electricity because
(a) Each carbon atom is bonded to three other carbon atoms.
(b) One of the bonds connecting the Carbon atoms is a double bond.
(c) Bonds are strong.(d) Carbon atom is sp hybridised.

Find Least Common Multiple (LCM). 1) 5 and 15 = ...