Problems-Questions-Chemistry,Maths,Physics, Feb 15

Chemistry
Alkane

A single substitution of H atom in an alkane of molar mass 72 g mol‾ ¹ by chlorine produces only one product.

a. 2-methylbutane
b. 2,2-dimethylpropane
c. n-pentane
d. n-butane



Mathematics

Chapter: Solutions of Triangles

If in a triangle ABC, sin A, sin B, and sin C are in arithmetic progression, then

a. the altitudes are in A.P.
b. the altitudes in G.P
c. altitudes are in H.P.
d. the altitudes are equal



Physics
Friction

A fireman weighing 80 kg slides down a pole.If the resisting force of friction is a constant 720 N, his acceleration measured in m/sec² is:

a. 0.0
b. 1
c. 0.01
d. 0.11

Questions-Problems - Chemistry - Physics- Mathematics - Feb 15

Chemistry – Chemical equilibrium

The pK_a of acetylsaliclic acd (aspirin) is 3.5. the pH of of gastric juice in the human stomach is about 2 to 3 and the pH in the small intestine is about 8. Aspirin will be

a. unionized in the small intestine and in he stomach.
b. completely ionized in the small intestine and in the stomach.
d. ionized in the stomach and unionized in the small intestine.
d. ionized in the small intestine and almost unionized in the stomach

For answer visit
http://www.orkut.co.in/Main#CommMsgs.aspx?cmm=39291603&tid=5302730322104261825

Physics

Physics Newton’s Laws

A body weighs 8 gm when placed in one pan and 18 gm when placed on the other pan of a false balance. If the beam is horizontal when both the pans are empty, the true weight of the body is

a. 12 gm
b 13 gm
c. 15 gm
d. 15.5

Desire, Determination and Tenacity

Desire the root of all action. Unless there is desire there can be no action.

But to yield results, desire must be translated into determination. A commitment to achieve the desired result must be explicit. In the endeavour there will enough testing moments. One gets tired, exhausted and bored. There has to be generous spirit which will rejuvenate you after every tiresome day. One has to be tenacious and tough. Whether the endeavour stretches or compresses you, you have to be ready to come back to normal state quickly and restart your action.

Come what may, you should not let go of your dreams. don't give up till the last minute of an opportunity.

Source:
Will to Change, by Devdutt Pattnaik, Corporate Dossier, Economic Times, 6 February, 2009, Page 3