We cannot have isomers of first three members of alkane series. Give reasons to justify this statement. Draw the structures of two isomers of pentane, `C_5H_12`.

Trophical regions are likely to have more biological diversity than temperate ones. Give two reasons to justify the statement.

Write IUPAC names of all the structural isomers C_5H_10

Give the isomers of structural formula C_4 H_10 (butane)

Indicate the types of isomerism exhibited by the following complexes and draw the structures for these isomers: K[Cr(H_2O)_2(C_2O_4)_2]

A farmer harvests his crop and expresses his harvest in three different ways: (a) I have harvested 10 quintals of wheat. (b)1 have harvested 10 quintals of wheat today in one acre of land. (c) I have harvested 10 quintals of wheat in one acre of land after 6 months from sowing. Do the above statements mean one and the same thing. If your answer is yes, give reasons. And if your answer is 'no' explain the meaning of each expression.

Two dice are thrown. The events A, B and C are as follows: A: getting an even number on the first die. B: getting an odd number on the first die. C: getting the sum of the numbers on the dice le 5 . state true or false: (give reason for your answer):- A and B are mutually exclusive

Direction. In the follwing questions, a statement of assertion is followed by a statement of reason. While answering a question, you are required to choose the correct are out of the given four responses and mark it as (A)If both assertion and reason are true and reason is the correct explanation of the assertion, (B) if both assertion and reason are true but reason is not correct explanation of the assertion. (C) if assertion is true, but reason if false, (D) if both assertion and reason are false Assertion : We cannot think of magnetic field configuration with three poles. Reason: A bar magnet does exert a torque on itself due to its own field.

Direction. In the follwing questions, a statement of assertion is followed by a statement of reason. While answering a question, you are required to choose the correct are out of the given four responses and mark it as (A). If both assertion and reason are true and reason is the correct explanation of the assertion, (B) if both assertion and reason are true but reason is not correct explanation of the assertion. (C) if asssertion is true, but reason if false, (D) if both assertion and reason are false Assertion : Electric appliances with metallic body e.g., heater,s presses etc, have three pin connections, whereas an electric bulb has two pin connection. Reason : Three pin connections reduce heating of connecting cables.

5 people of a locality were asked about the time they spent in a week in doing social work. They told the number of hous as: x,x+3,x+6,x+7,x+4. find the mean number of devoted by first three members. If mean number of hours of 5 persons is 11 hours, what values do we draw from above data?

Two dice are thrown. The events A, B and C are as follows : A : getting an even number on the first die B: getting an odd number on the first die C : getting the sum of numbers on the dice le 5 . State true or false (give reason for your answer): A and B are mutually exclusive.