Guesspaper Chemistry 9th,10th Federal Board 2009

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Class 9th,10th Federal Board 2009
Paper:Chemistry (Objective Type) Time Allowed: Max.Marks:
Note:Use this paper to write the answers to the objective questions.No marks will be awarded for cutting,over-writing or using a pencil.This paper must be tagged with the answer-book.
1. Insert the correct option.
(i) In Phlogiston theory, when a substance is burnt.the phlogiston escape into air. What is the thing left behind?
(a) Iron pyrite (b) Royal wate (c) Clax (d) Calcination
(ii) When a solution of Copper Sulphate is treated with magnesium metal, what will happen to the blue colour or copper sulphate?
(a) Turn pink (b) Discharged (c) Turn light pink (d) No changes

(iii) An atom is like a positively charged ball studded with negatively charged electrons at some places. what name can be given to it?
(a) Bohar's atomic modle (b) Rutherford atomic modle (c) Hund's modle (d) Plum pudding modle
(iv) A very small unot of length used to measure the atomic radius as 10-9 part of a meter is called?
(a) Nanometer (b) millimeter (c) Hund's (d) None
(v) Which one of the molecule / ions given below has the highest polarity between atoms:
(a) H_Cl (b) O_H (c) Co2 (d) H_H
(vi) In winter. sea water is frozen forming an ice layar which floats over water. Beneath it aquatic animals enjoy their life. This happens because the ice layer behave as:
(a) Good conductor of heat (b) Bad conductor of heat (c) Partially conductor of heat (d) none of these
(vii) Solute ions surrounded by solvent molecular in a solution are called solvanted ions.if the solvent is water, these ions are called hydrated ions. what will this process be called?
(a) Hydrated (b) Hydrolysis (c) Hydration (d) solvation
(viii) In an acid base titration using phenolphthalein as an indicator, we observe light pink colour at one stage, What does it indicate?
(a) Reaction will be completed in a while. (b) Reaction is proceeding
(c) Reaction is completed (d) Reaction is just started
(ix) What is the best and cheapest method for sterilization of water, that is also most effective in destroying pathogenic bacteria?
(a) Boiling (b) Clark's method (c) ion exchange method (d) Chlorination
(x) Tyres are used in automobile. they are usually black in colour and stiff. What is the substance that given them such properties?
(a) Rubber (b) Activated (c) Carbon black (d) Carbon wood
(xi) Carbon monoxide is very dangerous for health and causes suffocation. This happens when absorption of oxygen in blood is hindered. What causes this hindrance?
(a) Carbon monoxide itself (b) Carboxy haemoglobin
(c) Carboxy carbon monoxide (d) Haemoglobin
(xii) Gold and platinium are not dissolved even in all the storng acids, except in aqua regia which is a 3:1 mixture of HCL and NHO3. What is it that givens aqua regia this solubility?
(a) clorine gas formation (b) Greater amount of HCL
(c) Formation of soluble ions (d) Formation of soluble chlorides
(xiii) The transition temperature between two allotropes of sulphur is 96*c , which two allotropes does it refer to?
(a) Rhombic sulphur and monoclinic sulphur (b) Monoclinic sulphur and plastic sulphur
(c) Rhombic sulphur and plastic sulphur (d) Plastic sulphur and needle-e-like sulphur
(xiv) Iodized table salt helps to prevent goiter. this iodized salt is obtained by mixing table salt with:
(a) 0.002% Potassium iodide (b) 0.02% Potassium iodied
(c) 0.02% potassium chloride (d) 0.025% Potassium chlorid
(xv) What is the process called when roasted ore is melted in the blast furnace along with mixture of coal and sand?
(a) Roasting (b) Jugging (c) Smelting (d) skimming
(xvi) When ethyne is passed through a red hot iron tube, benzene is formed. What is the reaction called?
(a) Polymerization (b) Combustibility (c) Monomerization (d) Halogenation
(xvii) There are different methods for preservation of food.One of them is preservation by irradiation what are the most suitable rays used for it?
(a) Alpha rays (b) Helium nuclei (c) Gamma rays (d) Beta rays
(Subjective)
2- Attempt any FOURTEEN parts.
(i) Diatomic hydrogen is agas.it can react with different compounds to form products. Write balanced equation along with conditions for the prepration of following products to form hydrogen.
(a) Phoispine (b) Methyl Alcohol (c) Ethane
(ii) Silicone is found in nature in combined form as silicon dioxide and silicate mineral.\
(a) Draw the linkage of methyl (b) Write the reaction of silicone dioxide with calcium phosphate
(c) Write names of two naturally occurring crystalline forms of silicone dioxide.
(iii) The binary compounds (oxides) of oxgen on nthe basis of the valance number of oxygen are classified into diffrrent groups.
(a) Write name of their main oxides. (b) Give two examples of oxides, Whare valance number of oxygen is 1/2.
(iv) Free sulphur can exist in several allotropes. Heat has remarkable effect on sulphur changing one alllotrope into other.
(a) Name the alklotropes of sulphur (b) What happens when molten sulphur is heated?
(c) poured into cold water, which allotrope is formed?
(v) Ammonia is manufactured by reactrion between Nitrogen and hydrogen. These two gases are compressed to 200 atmospheric pressure at 400_500 C.
(a) Write the equation including state symbols for the formation of ammonia.
(b) If nitrogen gas used in above reaction is prepared in laboratory. write suitable reactions for its preparation by the downward displacement of water.
(vi) Formation of different colours of precipitate in chemical reaction indicate presence of different compounds or ions. Similarly, the halides are also confirmed by the colour of their precioitates.
(a) Write suitable chemical reaction for preparation of each, which can differentiate between all the halides formed.

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(vii) Aluminium is extracted form alumina by hall's process.
(a) Write the principal of the process. (b) Write chemical reaction occurring in the process.
(c) What are the functions of molten cryolite in the process?
(viii) Methane is a major component of natural gas. It is also called marsh gas because it is found in marshy places.
(a) how is methane prepared in laboratory form sodium ethanoate?
(b) It is not affected by acids or alkalies in laboratory under normal condition. Why?
(c) Discuss and draw structure of metane.
(ix) The given diagram represents the manufacturing of sodium hydroxide on commerical scale.
(a) Write name of the cell. (b) Name the suitable electrolysis used for the process.
(c) Write the equations for the reaction for the reaction that occur at their respective eletrodes along with their overall reaction
(d) Name the product which is re-usedin this process.
(x) Empirical formula is also called the simplest formula. sand is represented by an empirical formula SiO2.
(a) Draw the structure of SiO2, its molecular mass is 60, what will be its molecular formula?
(b) If the empirical formula of compound CH2O, its molecular mass is 60,what will be its molecular formula?
(c) Name the molecular compound.
(xi) Chemistry is as old as the history of mankind earth. This modern era of chemistry is dependent on the period of scientific advancement in early period and Islamic period.
(a) Given the concept of aristotle. (b) Explain the formulation given by gibbs.
(c) What work was done by Abu-Rehman muhammad Al-Beruni?
(xii) The number of sub-shells present in ashell is equal to its principal quantum number (n).
(a) Give the number of sub-shell in n=4 and also name those sub-shells.
(b) Give the formula which given the miximum number of electrons in any energy level.
(c) Give increasing order of the energy of the sub-shells belonging to different shells.
(d) Give another name of a sub-shell.
(xiii) Many theories and concepts are given about the definition of acids and bases.
(a) Give Lewis concept about an acid and base. (b)Write a chemical equation which indicates the formation of a co-ordination covalent bond between Lewis acid and Lewis base.
(c) The sting of honey bee is acidic, whereas the sting of wasp is alkialine. What first acid will you provide to the affected persons of both insects?
(xiv) Electro-chemical series is the list of ions arranged in the order of their ease of discharge at the electrode.
(a) If a solution contains a mixture of ion,how will you find out? which ion will be discharged first and which will be discharge at the end by the help of this series?
(b) How is the basic principal for discharging of ions in Electro-chemical series deviated by the nature of the Cathode material used?
(xv) The concertation of a solution can be expressed in different ways.
(a) How is it expressed using precentage by volume? Give example.
(b) Determine the amount of sodium carbonate (Na2CO3) required to prepare 200cm3 of M/2 solution. Molar mass of Na2Co3 is 106.
(xvi) Physical and chemical properties of elements gradually change in groups and periods.
(a) What trend is shown by atomic radii in periods?
(b) Give reasons in support of your above answer.
(c) Define electron affinity. give its trend in any period.
(xvii) With the help of chemical equations, explain Clark's method for the removal of temporary hardness of water.
(xviii) Give at least six points (postulates) of ionic theclassified? Define each class and explain with help of an example.

NOTE: Attempt any Two questions. (2x13=26)
3- Iron is extracted form its ores.blast furnace is used for this purpose.
a Draw labeled diagram of the blast furnace.
b how is carbon monoxide used as reducing agent in this process? Write all chemical reactions with carbon monoxide in this regard.
c What is slag? How is it produced in this process? Give reactions.
d Give the name of iron obtained from blast furnace.
e How is nitric acid prepared in industry by Ostwald's method? Explain with the help of chemical reactions.

4.a- State vital force theory and give prepration reaction of urea.
b. Defination isomerism. Give isomers of butane.
c. Identify the given functional groups:
(i)_COOH (ii) _OH (iii) C_X
d. Define law of multiple proportions and giveone example in its support.
e. 35g of limestone (CaCO3) react with an excess of hydrochloric acid according to the given equation. How many moles and grams of calcium chloride will be produced?
CaCO3 + 2HCl —> Cacl2 + H2O +CO2
(Ca=40, C=12, O=16, Cl=35.5, H=1)

5.a- How are atoms arranged in a metal and how can the shape of a metal be changed? Explain giving diagram.
b. Define hydrogen bonding. Name the atoms involved in this bonding and explain why they are involved? Give example of water and hydrogen fluoride.
c. Define a solution. Identify solute and solvent present in the given solutions.
(i) Hydrogen gas absorbed in palladium.
(ii) Carbon particles in air.
(iii) Alloy as (ph+sn).
(iv) Alcohol in water.
d. Give postulates of Bohr's atomic modle.
e. Define law of triads and give example.

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