Physics, Chemistry, Mathematics Forums

In all the books it is written that a buffer solution can be made with weak acid(e.g.CH3COOH) and strong base (e.g.NaOH).Suppose i have some CH3COOH solution.Then I have foll. equilibriums established:

CH3COOH^----><----CH3COO^- + H⁺      -----(1) ---Ka(small)                      AND

CH3COO^-+H₂0^----><----CH3COOH+OH^-  ----------(2)----Kh(small)

if i add some NaOH then reaction (2) is favoured backwards and almost all of my added NaOH gets converted to acetate ions as 1/Kh is very very large.But then b'coz of increase of acetate ions reaction (1) is favoured and almost all extra ions get converted to acid as 1/Ka is also very very large.

Then increase in acid again causes backward reaction of (2) and ions formed again and the whole process is repeated again and again.So at the end poor OH^- is almost negligible.

This is just an example but if we speak in general then i can't maintain a pH of 10,11,etc as then in that case we are assuming [OH]=10⁴etc. which i have proved above is impossible.

Plz give your suggestions on this!!!

Consider  two wires P1Q1 AND P2Q2. Both of them are sliding on smooth rails.The wires have a resistance of 2ohms.moving with same speed equal to 5cm/s and are connected to a 19 ohm resistor.The length of the wires is same and is equal to 4cm/s.Magnetic field is into the page and is 1T. Find the current in 19 ohm resistor when the wires are moving to the right.

I have one more doubt in this that when the wires are moving to the right and magnetic field is inside the page, emf is induced in the wires and thus, batteries are generated. Both of these batteries have higher potential at the top and lower potential at the bottom.Thus, batteries are opposing each other and hence there should be no current in the circuit at all.   But when I did mathematics of this question I found that current in the 19 ohm resistor is 1 mA. However answer is 0.1mA.Please answer my doubt .

What is the product of rxn:

1-Bromo-2-Methyl Benzene --------------> ?????
Mg/ether
CO₂/H₃O⁺
KMnO₄/OH^-
H⁺

Triangle ABC is scalene . If angle A is maximum and angle C is minimum.Then the value of sin(A/2) and cos(C/2) is

a. 0.71 and 0

b. -1 and 0

c. 0.85 and 0.5

d. 1 and 1

Please tell me the answer with some hints.

If (a+b+c+d+e)²=a² then value of a lies between

1. (0,infinity)

2. (-infinity,+infinity)

3. [0,infinity)

4. none of the above

(Edited by INDIANET @IIT-JEE - original submission Monday, 4 December 2006, 08:36 PM - large fonts)

Internal bisector of angle A of triangle ABC meets side BC at D. Through D,a line drawn perpendicular to AD intersects the side AC at E   and  the side AB at F.If a,b,c represent the sides of triangle ABC, THEN

1. AE IS H.M. OF b and c
2. AD=[2bc/b+c ]cosA/2
3. EF=[4bc/b+c]sinA/2
4. The triangle AEF is isosceles.

Q. An organic compound A, C₆H₁₀O₃ is an ester. A reacts with NaOH and I₂ to give CHI₃ and a salt which is hydrolysed in acidic medium to give B. On de-carboxylation, B gives an organic compound C.
Then:
the organic compound A may be:
a) C₂H₅COCOOC₂H₅
b) CH₃COCH₃COOCH₂CH₃
c) CH₃COCOOCH(CH₃)₂
d) CH₃COCH₂CH₂COOCH₃

The organic compound B and C are:
a) (CH₂)₂(COOH)₂ ; CH₃CH₂COOH
b) (COOH)₂ ; HCOOH
c) CH₂(COOH)₂ ; CH₃COOH
d) CH₂(COOH)₂ ; CH₃CH₂COOH

Please give me your answer as soon as possible...

we know from maxwells theory that a time varying magnetic and electric field produces emw  then shouldnt an ac generator also produce emw as it produsec time vaying electric field from a time varying magnetic field

pleas clear this doubt 

What will calcium hydroxide form on exposure to air? Will it form calcium oxide or calcium carbonate? If your answer is calcium carbonate, then why does calcium hydroxide doesn't turn milky just on exposure to air in Lab. I have great doubt in this. Please clear it. It came in one of my exams... and i marked it as calcium oxide.

Give your suggestions to the ques. i have earlier typed please....