KPK Board 12th class Chemistry Ch 24 Analytical Chemistry questions answers

We are providing all Students from 5th class to master level all exams preparation in free of cost. Now we have another milestone achieved, providing all School level students to the point and exam oriented preparation question answers for all science and arts students.

After Online tests for all subjects now it’s time to prepare the next level for KPK board students to prepare their short question section here. We have a complete collection of all classes subject wise and chapter wise thousands questions with the right answer for easy understanding.

We provided 12th class Chemistry short questions answers on this page of all KPK boards. Students of KPK boards can prepare the Chemistry subject for annual examinations.

In this List we have included all KPK boards and both Arts and Science students. These Boards students can prepare their exam easily with these short question answer section

Malakand Board 12th classes short questions Answer

Mardan Board 12th classes short questions Answer

Peshawar Board 12th classes short questions Answer

Swat Board 12th classes short questions Answer

Dera Ismail Khan Board 12th classes short questions Answer

Kohat Board 12th classes short questions Answer

Abbottabad  Board 12th classes short questions Answer

Bannu Board 12th classes short questions Answer

All above mention KPK Boards students prepare their annual and classes test from these online test and Short question answer series. In coming days we have many other plans to provide all kinds of other preparation on our Gotest website.

How to Prepare KPK Board Classes Short Question Answer at Gotest

  • Just Open the desired Class and subject which you want to prepare.
  • You have Green bars which are Questions of that subject Chapter. Just click on Bar, it slides down and you can get the right answer to those questions.
  • You can also Rate those question Answers with Helpful or not to make it more accurate. We will review all answers very carefully and also update time to time.

Now you can start your preparation here below

Why magnesium perchlorate is used as H2.0 absorber?

Magnesium perchlorate is an excellent dehydrating agent used in the combustion analysis. It does not become sticky when exposed to air and the glass tube can easily be cleaned.

Acetic acid contains only C, H and O.A 5gm sample of acetic acid is completely burnt. It gives 3.00gm of water and 7.33gm of CO, is produced. What is the mass percentage of each elements in acetic acid. Also calculate the empirical formula of acetic acid.


mass of Acetic acid = 5gm

mass of H2O=3gm

mass of Co2 = 7.33gm

%age of elements =?

Empirical formula =?

Mass of CO2/mass of compx12/44x100o

C =7.33/5×12/44×100=39.7

%age of H2, = mass of H20/mass of compx2.02/18 x100


%age of H2 = 0.6×0.11×100 = 6.6%

%age of O2, = (100-%C+%H)

%age of O2, = 100-39.7 +6.6

%O2, = 53.7%

Moles of C = 39.7/12 = 3.30moles

Moles of H = 6.6/1.01 = 6.5

Moles of O2,=53.7/16=3.35

Molar Ratio

C                 :          H                 :       O

3.30/3.30:     6.5/3.30     :3.35/3.30

1              :         1.95       : 1.01

As 1.96 ͌ 2 So

С      H       O

1      2       1

So empirical formula acetic acid is CH2O

Isoprene is a liquid compound that can be polymerized to form synthtic. It is composed of 88.17% carbon and 11.83% hydrogen. Its me mass is 68.11g/mole. What are its empirical and molecular formulae?


%age of C = 88.17%

%age of H = 11.83%

Molar mass = 68.11g/mole

Empirical formula =?

Molecular formula =?

Moles of C – 88.17/12=7.34mole

Moles of H2, = 11.83/ 1.01=11.83

Molar Ratio =

C                     :                 H

7.34/7.34      :         11.83/7.34

1                      :         1.61

Now multiply it with 5 to get simple ratio

Simple ratio

C        :      H

5 (1       :   1.6)

C5H8  empirical formula.

Now molecular formula if isoprene

Empirical formula mass = C5H8

= 60+8= 68g

n=M.mass 68/ E.F.mass= 68/68=1

M.Formula = nx Empirical formula

= 1xC5H8

M.formula = C5H8

This shows that both empirical and molecular formulas of isoprene’s are same



Why modern method of analysis is superior over classical methods of analysis?

Modern methods of analysis are superior over classical methods because of the following reasons.

  1. Small amount of chemicals are required.
  2. Chemicals are not wasted in large amount.
  3. These methods are rapid and less time consuming.
  4. They give more accurate results.
  5. These methods are simple and do not involve much chemistry as compared to the classical methods.
Write down the main functions of IR, UV-visible and NMR spectroscopy?

(i) IR Function: The main function of IR spectroscopy is identification of different functional group present in an organic compound.

  1. ii) UV-Vis: The main function of UV-visible spectroscopy is to measure the conjugation of double bonds.

iii) NMR: The main function of NMR spectroscopy is to determine the number and kind of protons present in an organic compound.

  1. iv) Mass Spectroscopy: The main function of mass spectroscopy is to give informations about molecular mass of an organic compound.

Conclusion: All these four techniques helps the organic chemist to determined the structure of an organic compound.

What is meant by Beer-Lambert's Law? Explain.

Ans. Beer-Lambert’s Law state that the ”quantity of light absorbed by a substance dissolved in a fully transmitted solvent is directly proportional to the concentration of substrate and path length of light through the solution.


Why it is necessary to use quartz cuvets in the U.V region, but less expensive glass or plastic cuvets are acceptable in the visible region.

The quartz cuvets are transparent in the UV region while glass cuvets shows maximum absorbance in UV region. However they can be used in visible region where they are transparent.

You Can Learn and Gain more Knowledge through our Online Quiz and Testing system Just Search your desired Preparation subject at Gotest.

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button