9th Class Chemistry Guess Paper 2021 Lahore Board
9th Chemistry Guess Lahore Board
Questions # 1
- Give two properties of neutrons.
- How many neutrons are present in C-12 and C-13?
- Do you know any element having no neutrons in its atoms?
Questions # 2
- Why the second ionization energy of an element is higher than first one?
- What do you mean by blocks in a periodic table and why elements were placed in blocks?
- For an element Z = 92, A = 238. Calculate the number of electron and proton in it.
- What is the definition of the element according to the Robert Boyle?
- What is the significance of the symbol of an element?
- Define Boyle’s Law and verify with an example.
- What type of elements from metallic bond?
- Define Avogadro’s number.
- Which element has the highest electro negativity?
- What type of elements have tendency of sharing of electrons?
- Why and how elements arranged in a period?
- What type of elements are metals?
- Write down the names of elements of group 1 with their symbols?
- Define Boyle’s rule?
Questions # 3
- Write two chemical properties of metals and non-metals.
- Define metal, give two examples.
- Write down the name of four least reactive metals.
- Compare any four physical properties of metals and non-metals.
- What are important physical characteristics of metals?
- Why reactivity of metals increase drown the group?
- How non-metals are essential part of our body structure?
- Which metal is used for metal work?
- State the physical properties of metals
- What is the trend of variation it densities of alkali metals?
- Metals are good conductor of electricity. Why?
- What are transition metals?
- How oxygen reacts with group II A metals?
Questions # 4
- Why silver and gold are least reactive?
- Give properties and uses of gold?
- Which is lighter than aluminum of gold?
- Give the applications of silver. Why platinum is used for making Jewellery?
- Can pure gold be used for making electrical wires?
Questions # 5
- Give the Properties of dipole-dipole forces.
- Define dipole interactions. How are they created?
Questions # 6
- Write down any two properties of canal rays.
- Give two properties of positive rays.
- Write down two properties, of cathode rays.
- What conclusion you derive from these properties.
- How are cathode rays produced?
- What is the nature of charge on cathode rays?
- What are its five major characteristics?
Questions # 7
- Define atomic mass unit. Why is it needed?
- Define atomic number and mass number.
- What are SI units of atomic radius?
- Define Tri-atomic and Hetero-atomic.
- Why do atoms react?
- How can you define atomic radius?
- What is Luther Meyer’s atomic volume curve?
- What is meant by atomic size? Write its unit.
- What are the salient features of Rutherford’s atomic model?
- How Rutherford discovered that atom has a nucleus located at the centre of the atom?
- What are the defects of Rutherford atomic model?
- Give two postulates of Bohr’s atomic theory.
- How it is related to gram?
- What is the relative atomic mass?
- Find out the mass of 3 moles of oxygen atoms.
- Why the size of atom decreases in a period?
- How to atoms follow octet rule?
- What is trend of atomic radius in period and group?
- Calculate the number of atoms in 10 grams of Aluminum (Al).
- Differentiate between Homo atomic and Hetero atomic molecules.
- How is periodicity of properties dependent upon number of protons in an atom?
- Calculate the number of moles, number of molecule atoms present in 6 grams of water.
- How was it proved that electrons are fundamental particles of an atom?
- Give basic postulates of Bohr’s atomic theory.
- Give the electronic configuration of carbon atom.
Questions # 8
- Give the physical properties of sodium and its uses.
- Write any two uses of sodium.
- Why does sodium make ionic bond with chlorine?
- Why does sodium forma chemical bound with chloride?
- Why magnesium is harder than sodium.
Questions # 9
- Write down two uses of calcium.
- Give physical properties of calcium and its uses.
- Why calcium is more electropositive tan to magnesium?
- Write the chemical formulae of Aluminium Sulphate and Calcium Phosphate.
Questions # 10
- Define and explain Charles’s Law of gasses.
- Whether the density of gases increases on cooling? Explain.
- Why are the densities of gases lower than that of liquids?
- Why the gases are compressible?
- Why noble gases are not reactive?
- Can you cool a gas by increasing it volume?
Questions # 11
- What is meant by volume / volume %?
- What do you mean by %-mass / mass?
- Give the example and formula of mass by volume percent.
- There are 3.01 x 1023 molecules of CO2 present in a container.
- Calculate the number of moles of coal in the given mass.
- Calculate the number of moles and its mass. You have a piece of coal (carbon) weighing 9.0 grams.
- How can you differentiate between molecular formula, formula mass and empirical formula?
- Calculate the number of moles of coal in the given mass.
Questions # 12
- Briefly describe its principle, purpose and procedure.
- Define electroplating.
- What are non-electrolytes, give example?
- How electroplating of tin on steel carried out?
- How electroplating of zinc is carried out?
- In electroplating of chromium, which salt is used as an electrolyte?
- Which solution is used as electrolyte in Nelson’s cell?
- Differentiate between strong and weak electrolytes.
Questions # 13
- Define Galvanic cell.
- What is salt bridge?
- How the half cells of galvanic cell are connected?
- What is the difference between anode and cathode?
- What happens to cathode in the galvanic cell?
- What is the function of salt bridge?
- Write two differences between electrolytic and galvanic cell.
Questions # 14
- What do you mean by groups and periods in the periodic table?
- What do you mean by periodic function?
- What are the Defects in Long Form of Periodic Table?
- Define electron affinity.
- Explain the trend of electron affinity in periodic table.
- Describe its trend in periodic table.
- What do you mean by shielding effect?
- Discuss the important features of modern periodic table.
- Explain its trends in periodic table.
- Describe its trend in the periodic table.
- What is the difference between Mendeleev’s periodic law and modern periodic law?
- What are Halogens? Describe the position of halogen in periodic table?
Questions # 15
- Explain the term oxidation on the basis, of electrons concept with an example.
- Define valiancy.
- Describe oxidation and reduction in term of loss or gain of electron.
- What is the oxidation number Carbon in Na2CO3?
- Calculate oxidation number of nitrogen in HNO3.
- What is reduction?
- Explain with an example. Describe the rules for assigning the oxidation state.
- Oxidation and reduction proceed simultaneously.
- What is difference between valiancy and oxidation state?
- Explain the term oxidation on the basis of electronic concept with an example.
Questions # 16
- Write down general electronic configuration of carbon family.
- Write down the electronic configuration of chloride ion.
- Write down the electronic configuration of Na.
- Write down electronic configuration of chlorine.
- Write down the electronic configuration of Be and Ne.
Questions # 17
- What is the maximum capacity of a shell?
- Differentiate between shell and subshell.
Questions # 18
- A solution contains 50 g of sugar dissolved in 450 g of water.
- What is the unit of concentration?
- What is concentration of this solution?
Questions # 19
- What is meant by carbon dating?
- What is mole? Calculate the number of moles In 84 gram carbon.
Questions # 20
- Define chemical bond.
- What is meant by metric bond?
- Differentiate between lone pair and bond pair of electrons.
- Differentiate between Polar and non polar covalent bond.
- Describe at least two necessary conditions for the formation of a covalent bond.
- How coordinate covalent bond is formed in the hydronium ion?
- What is the cause of polarity in covalent bond?
- What type of covalent bond is formed in nitrogen molecule?
- Why have water polar covalent bonds?
- Define ionic bond, explain different steps in the formation of NaCr.
- What is a triple covalent bond, explain with an example?
- What is a coordinate covalent bond? Explain it with example.
- What is metallic bond? Explain the metallic bonding with the help of a diagram.
- Explain double covalent bond with the help of an example.
- Define hydrogen bonding. Explain how these properties affect the physical properties of compound.
- Define ionic bond and Why ionic compounds are easily soluble in water?
- Define coordinate covalent bond. How it is formed. Explain with examples.
Questions # 21
- Differentiate between Oxidizing agents and Reducing agents with the help of an example.
- Define reducing agent.
Questions # 22
- Which form of sculpture exists at room temperature?
- Define transition temperature.
- What is absolute temperature?
- What is general principle of solubility?
- What is absolute zero temperature?
- What is the effect of temperature on solubility?
- Define pressure and write its unit.
- What is vapor pressure and how it is affected by intermolecular forces?
- Why is vapour pressure higher at high temperature?
- Define atmospheric pressure.
Questions # 23
- Briefly describe the electrolysis of water.
- What is electrolysis?
- Describe the process that take place in the electrolysis of molten NaCI.
Questions # 24
- How can distinguish between solution and pure solvent?
- How you can explain the solute-solvent interaction to prepare a NaCl solution?
- Define solute and solvent.
- Differentiate between solute and solvent with examples of each.
Questions # 25
- Define aqueous solution.
- What does mean by unsaturated solution?
- Define super saturated solution When we dissolve 20 g of NaC1 in 400 cm3 of solution, what will be its molarity?
- What is molarity and give its formula to prepare molar solution?
- How much NaOH is required to prepare 500cm3 of 0.4M solution?
- What is the major difference between a solution and a mixture?
- Describe different ways of expressing the percentage composition of a solution.
- Describe Nelson’s Cell for the manufacture of Caustic soda from brine solution.
- What is meant by Molar Solution? How it is prepared.
- Compare the characteristics of solution, colloid and suspension.
- Why a solution is considered mixture?
- Differentiate between dilute solution and concentrated solutions with a common example.
- Why the alloys are considered solutions?
Questions # 26
- Define electron electivity.
- Define electro chemistry.
- How electro negativity does differ from electron affinity?
- What is electro negativity?
- What is the relationship between electro positively and ionization energy?
- What is relationship between electro negativity and polarity?
- Describe the trends of electro negativity in a period and in a group.
Questions # 27
- Why chlorine can accept only 1 electron?
- When does an electron emit or absorb energy?
Questions # 28
- What are synthetic adhesives?
- What you know about Epoxy adhesives?
Questions # 29
- Write any five characteristics of mixture.
- What is meant by mixture?
- State the reason soft drink is a mixture and water is a compound.
- Why does ice float on water?
- Find out the molecules in 9 gram of water.
- State any three difference between compound and mixture.
- How does homogeneous mixture differ from heterogeneous mixture?
- State three reasons why do you think air is a mixture and water a compound.
- Why does not the suspension form homogeneous mixture?
Questions # 30
- Describe the phenomenon of diffusion in liquids along the factors which influence it.
- Define diffusion.
- What is difference between diffusion and effusion?
- Describe the factors which influence the diffusion of liquid.
Questions # 31
- Write the name of factors which effect evaporation.
- Define evaporation.
- What do you mean by evaporation, how it is affected by surface area?
- What is difference between boiling point and evaporation?
- What is the relationship between evaporation and boiling point of liquid?
- Evaporation causes cooling. Explain.
Questions # 32
- What did you mean by the Thermal conductivity of the metallic compounds?
- What do you mean by metallic character?
Questions # 33
- How can a non-spontaneous reaction be carried out in an electrolytic cell? Discuss in detail.
- What are spontaneous and non spontaneous reactions?
Questions # 34
- Distinguish between amorphous solid and crystalline solid.
- Define crystalline solid and give its two examples.
Questions # 35
- What is difference between colloids and suspensions?
- How can you justify the milk is colloid?
- Why are the colloids quite stable?
- What is meant by colloid? Give two examples.
Questions # 36
- Why are liquids mobile?
- Write two properties of liquids.
Questions # 37
- Write four properties of covalent compounds.
- What are ionic and covalent compounds?
- Ionic compounds are solids justify.
- Write two properties of solids.
Questions # 38
- Give the trend of ionization energy in a period.
- Define Ionization energy.
- Why ionization energy Na is less than Mg?
- Why the ionization energy of Na more than K?
- What is second ionization energy and how is it represented?
Questions # 39
- What are radioactive isotopes?
- Write isotopes of chlorine.
- Give one example each of the use of radioactive isotope in medicine and radio therapy.
- Describe some major applications of radioactive isotopes in our surroundings.
- Write down any three isotopes of uranium.
- What is isotope? Discuss the structure of Isotope with suitable examples.
- Give the applications of isotopes in the field of radiotherapy and medicines.
- Describe the isotope of hydrogen with diagram.
- What is an isotope?
Questions # 40
- Write at least two physical properties of magnesium.
- What is meant by magnesium ribbon and where it use?
- Write down any two uses of magnesium.
Questions # 41
- Briefly describe the electrolytic refining of copper.
- What is electrolytic cell briefly describe its construction and working?
- Give the difference between electrolytic cell electro chemical cells.
Questions # 42
- What is inolarity? Write its formula.
- Describe the significance of chemical formula.
Questions # 43
- Write different types of molecules What is the difference molecule and molecular ion?
- What is a molecule?
Questions # 44
- Write a note on the construction of a Daniel Cell.
- Briefly describe the construction and working of Daniel cell?
Questions # 45
- Write any two chemical properties of halogens.
- Write down the important chemical reactions of halogens.
Questions # 46
- Why we stir paints thoroughly before using?
- Define substance. Mole is SI unit for the amount of a substance. Define it with examples.
- Define boiling point and also explain the factors which are affected on it?
- Explain classical theory of radiation
- Discuss the construction and working of a cell in which electricity is produced.
- Write a short note on Allotropy.
- Describe the classification of Dobereiner’s triads and give one example.
- What do you mean by cation and anion? Explain with examples.
- What are redox reactions?
- Give chemical reaction between methane (CH4) and chlorine (Ct2 ) in the presence of diffused light.
- Write the names of Electro chemical cells.
- Complete and balance the given chemical equation Na+H2
- Define analytical chemistry.
- Differentiate between periods and groups.
- Define empirical forthula with example.
- What is Metalloid?
- What is matter?
- Ionic compounds form solids. Justify.
- What do you mean by dynamic equilibrium?
- What do you mean by Pascal? How many Pascals are equal to I atm.
- What do you mean by solubility?
- What is meant by density?
- What is suspension?
- What is meant by condensation?
- What is meant by Brine?
- What is meant by chemical reactivity?
- What is Lewi’s Structure Diagram?
- What is % v/m ?
- What is electro positivity? Explain with an example.
- Define industrial chemistry.
- Define bio chemistry and give the scope of bio chemistry.
- Define physical chemistry.
- How can you differentiate between organic and inorganic chemistry?
- For what purpose is u-235 used?
- Explain ductile.
- Give experimental verification of Charles’s law.
- Define oxidizing agent.
- Define quantum theory.
- Define symbol and valency with example. What is meant by variable valency?
- Define homoatomic and hetroatomic morecule with examples.
- Define freezing point.
- Define malleable.
- Define effective nuclear charge.
- Define morality and writes its unit.
- Define nuclear fission reaction
- A patient has goiter. How will it be detected?
- Define Nuclear Chemistry.
- What is the difference between ions and free radicals?
- Write the definition of Duplet rule and Octet role.
- What is the nature of electrode used in electrolyzing of chromium?
- What is meant by periodicity of properties?
- What is difference between steel and stainless steel?
- Define Alkali metals and Alkaline earth metals.
- What is Dielectric Constant?
- What are intermolecular forces?
- Explain the term absolute zero.
- Name the by-products produced in Down’s cell.
- Why an iron grill is pointed frequently?
- How can you prove that angular momentum is quantized?
- Why is HF a weak acid?
- Why do you mean by malleability?
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