11th Class Chemistry Important Short Question Online Free

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• 11th Class Chemistry Ch 1 Basic Concepts Short Question Answers
• 11th Class Chemistry Ch 2 Experimental Techniques in Chemistry Short Question Answers
• 11th Class Chemistry Ch 3 Gases Short Question Answers
• 11th Class Chemistry Ch 4 Liquids and Solids Short Question Answer
• 11th Class Chemistry Ch 5 Atomic Structure Short Question Answers
• 11th Class Chemistry Ch 6 General features of Chemical bond Short Question Answer
• 11th Class Chemistry Ch 7 Thermochemistry Short Question Answers
• 11th Class Chemistry Ch 8 Chemical Equilibrium Short Question Answers
• 11th Class Chemistry Ch 9 Solutions Short Questions Answers
• 11th Class Chemistry Ch 10 Electro Chemistry Short Questions Answer
• 11th Class Chemistry Ch 11 REACTION KINETICS Short Question Answers

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11th Class Chemistry Important Short Question

• Define Fahrenheit scale.
• What is conjugate base of the acid?
• Define Evaporation,
• A weak acid has strong conjugate base. Justify.
• Explain why evaporation takes place at all temperatures.
• Define hydrolysis with example.
• Voltaic cell is reversible cell, State.
• Differentiate between hydration and hydrolysis
• What are isotopes? Why they have same chemical but different physical properties?
• What is mole? Why the sum of mole fractions of all components of a solution is always equal to unity?
• Define the octet rule.
• Define state of Equilibrium.
• What is the basic principle of crystallization?
• Define amorphous solids.
• Define optimum pH?
• What is vaccum distillation?
• Define polarizability.
• What is Lyman series?
• Define Balmer series.
• Define unit cell.
• Define vander wall’s equation.
• Justify that heat of formation of compound is sum of all the other enthalpies.
• Why is HF a weaker acid than HC1?
• Calculate the density of methane at STP.
• What are London dispersion forces?
• What do you mean by chemical equilibrium?
• Why regular air cannot be used in diver’s tank?
• What is the first law of thermodynamics?
• Give two statements of Raoult’s law.
• Why the dipole moment of SO2 is 1.61 D but that of SO3 is zero?
• The dipole moments of CO2 and CS2 are zero but that of SO2 is 1.61D.
• What are dipole-dipole forces of attraction? Explain with an example.
• What is the basic assumption of VSEPR theory, and discuss the shape of a molecule (BF3) containing three electron pairs?
• Define the term state function, give two examples.
• Write down two postulates of VSEPR theory.
• State the geometry of NH3 molecule on the basis of VSEPR theory.
• Explain the term enthalpy.
• The enthalpy of neutralisation of all the strong acids and strong bases has the same value. Justify.
• State enthalpy of combustion with example.
• Explain the term enthalpy of atomization.
• State Le-Chatelier’s principle and discuss the effect of change in concentration of a product on reversible reaction.
• Explain the term buffer capacity.
• Give the two applications of the solubility product.
• How the type of bonding affects solubility of compounds?
• What are buffer solutions? How a basic buffer can be prepared?
• Write two uses of buffer solution.
• Define solubility product. Give its one application.
• Depression in freezing point is a colligative property. Justify.
• What is meant by molality? Give its formula.
• Why Beckmann’s thermometer is used to measure the depression in freezing point?
• Why the NaCt and KNO3 are used to lower the melting point of ice?
• What is electrochemical series?
• Lead accumulators is a chargeable battery. Justify.
• How electrochemical series help us in determining the chemical reactivity of metals?
• What is difference between cell and battery?
• Differentiate between average rate and instantaneous rate.
• Why different liquids evaporate at different rates even at the same temperature?
• What is specific rate constant or velocity constant?
• How surface area affects the rate of a chemical reaction?
• What happens to the rate of a chemical reaction with the passage of time?
• What are enzymes? Give two examples in which enzymes act as catalyst.
• Why theoretical yield is greater than actual yield?
• Enzymes are specific in action. Justify.
• Law of conservation of mass has to be obeyed during stoichiometric calculation, give reason.
• What is vapour pressure? OR What is Dalton’s law of partial pressure?
• Write down stoichiometric assumptions.
• Write down the values of atmospheric pressure in four different units.
• What will be the effect of change of pressure on the synthesis of NH3?
• Lowering of vapor pressure is colligative property. Explain.
• Derive the units for gas constant R in general gas equation when pressure is in Nm-2 and volume in m3.
• What is the size of atom?
• What are defects in Rutherford’s atomic model?
• Why cationic radius radius is smaller than parent atom?
• Why the radius of an atom cannot be determined precisely?
• Why is the -radius of a cation smaller than its parent atom?
• Mg atom is twice heavier than that of carbon atom. Justify.
• The radius of first orbit of hydrogen atom is 0.529 A°. Calculate the radius of 3″1 orbit of hydrogen atom.
• Give the chemistry of electrolysis of aqueous solution of sodium chloride.
• What are the defects in Rutherford’s atomic model?
• Write the electronic configuration of Cr for which atomic number is 24.
• Write electrode reactions of electrolysis of fused sodium chloride.
• Define autocatalysis with an example.
• What are isotherms?
• Define Avogadro’s law.
• Give assumption of stoichiometry.
• Why is there a need to crystallize the crude product?
• Define transition temperature with an example.
• Write down the electronic configuration of Fe (26) and Br (35).
• Transition temperature is the term used for elements as well as compounds. Explain
• Give any two properties of neutrons. OR How neutrons were discovered by Chadwick? Give the equation of nuclear reaction involved.
• What do you know about internal energy of a system?
• State Hund’s rule and give an example.
• Define activation energy and activated complex.
• What is lattice energy? Give an example.
• What is electrolytic cell? What is the difference between metallic conduction and electrolytic conduction?
• Impure copper can be purified by electrolytic process. Explain.
• Differentiate between electrolytic and voltaic cell.
• Define standard electrode potential.
• Give chemical reactions taking place at anode and cathode in a fuel cell.
• Write down any two characteristics of enzyme catalysis.
• How fuel cells produce electricity?
• Define order of reaction. Give one example.
• Differentiate between Enothermic and Endothermic Reaction.
• What is half life method for the determination of order of a reaction?
• Define half life period. How is it used to determine the order of reaction?
• Differentiate between endothermic and exothermic reactions.
• How the values of equilibrium constant helps to predict the direction of a reversible reaction?
• The sum of the coefficients of a balanced chemical equation is not necessarily important to give the order of reaction justify.
• Radioactive decay is first order reaction. Justify.
• How the direction of a reversible reaction at any instant can be determined by Kc value?
• How the value of K, of a reaction helps to predict the direction of a reversible reaction?
• Define order of reaction with the help of an example.
• Define a spontaneous reaction.
• Write a nuclear reaction for the decay of free neutron.
• Why oxygen cannot be determined directly in combustion analysis?
• Write down nuclear reactions involved in the conversion of Cu into Zn.
• Write function of Mg (C CO-4)2 and KOH in combustion analysis.
• Define molecular ion, write its uses.
• What iS Boiling point? Why boiling point of H2O is greater than HF?
• Boiling needs a constant supply of heat, why? Why the boiling points of noble gases increase down the group?
• Differentiate between inter molecular forces. Differentiate between ion and molecular ion.
• State Moseley’s law. Write two importance of Moseley law.
• Define Pauli’s Exclusion Principle with an example.
• What is common ion effect? Give an example.
• Differentiate between Zeeman effect and stark effect.
• State Auf-bau principle and Pauli’s exclusion principle. State Pauli Exclusion Principle and Hunt’s rule.
• State Joule Thomson effect. Write its application.
• Give statement of ‘Distribution Law’.
• The electrical conductivity of metals decrease with the increase in temperature. Why?
• Mention two defects of Bohr’s model. According to Bohr’s model’ in which orbit electron can move?
• Define upper consulate temperature with example.
• How the wave nature of electron was verified experimentally? Explain electron gas theory.
• Differentiate between homogeneous catalysis and heterogeneous catalysis.
• Diamond is insulator and hard. Give reason. Diamond is hard and an electrical insulator. Give reason.
• What is difference between qualitative analysis and quantitative analysis?
• State spin quantum number (s) briefly. What is Planck’s quantum theory?
• Cathode rays are material particles. Explain with reason. Why of cathode rays is equal to that of electrons?
• Whichever gas is used in the discharge tube, the nature of the cathode rays remains the same. Why?
• Why the nature of cathode rays is independent of the nature of the gas used in discharge tube?
• How the K-series, L-series and M-series of x-rays spectrum are produced?
• Define ionization energy and write its variation in the periodic table.
• Give reason for the production of positive rays. OR Why — value for the cathode rays is just equal to that of electron?
• Name the factors which affect the ionization energy of an element.
• Why ionization energy decreases down the group although the nuclear charge increases?
• How does ionization energy vary in a group of periodic table?
• Define electronegativity. Give its trend in the periodic table.
• The bond angles of H20 and NH3 are not 109.5° like that of CH4. Although 0-atom and N-atom are SP3 hybridized like C- in CH4, give reason.
• Explain the term bond order. OR What is Bond Energy?
• The bond angles of H2O and NH3 are not 109.5° like that of CH4 although oxygen and nitrogen atoms are SP3 – hybridized. Why?
• How the nature of a chemical bond is predicted with the help of electronegativity values of two bonded atoms?
• Define coordinate covalent bond and give one example. OR it-bonds are more diffused than a-bonds. Give reason.
• Why n-bonds are more diffused than a-bonds? OR NH 3 and N F Shave different bond angles. Justify.
• Define bond order. Calculate bond order of hydrogen molecule.
• Define bond energy with two parameters which determine its strength.
• What is mass spectrum? OR Why atomic spectrum isline spectrum?
• Define empirical formula and molecular formula with example. Write four steps for determining empirical formula.
• Define spectrums. OR What is the difference between continuous spectrum and line spectrum?
• Define molecular formula of a compound. How is it related with its empirical formula? OR What Gram formula?
• What is solvent extraction?
• Boiling points of the solvents increase due to the presence of solutes. Justify it.
•  Why is the vapour pressure of a solution less than pure solvent?
• Calculate the value of R in SI unit. OR Calculate the value of gas constant It in SI-units.
• Write down the name of Eight solvent used in crystallization. OR Define distribution law and how it is helpful in solvent interaction.
• Give four fundamental postulates of kinetic molecular theory of gases.
• Write two faulty assumptions of kinetic molecular theory of gases.
• Derive Graham’s law of diffusion in the light of kinetic molecular theory of gases.
• Write down the faulty postulates of kinetic molecular theory of gases.
• Why one feels sense of cooling under the fan after bath?
• Explain Boyl’s law according to kinetic molecular theory of gases.
• Explain with reason, “Evaporation causes cooling.” OR One feels sense of cooling under the fan after bath. Explain with reason.
• Write down two applications of liquid crystals.
• How the liquid crystals help in the detection of the blockage in veins and arteries?
• Vacuum distillation can be used to avoid decomposition of a sensitive liquid. Explain with reason.
• Define isomorphism and polymorphism with example.
• Calculate mass of an electfon from its —e value. m
• What is the relationship between polymorphism and allotropy?
• What is mass spectrometer? OR Define relative atomic mass.
• Define Molar mass. OR State the law of mass action. OR What is Avogadro’s number? Give equation to relate the Avogadro’s number and mass of an element.
• Calculate fraction of total pressure exerted by oxygen when equal masses of CH4 and 02 are mixed in an empty container at 25°C.
• Calculate the mass of electron when its e/m value is 1.7588 x 10’1 C
• Calculate mass in kg of 2.6 x 1020 molecules of SO2. OR No individual neon atom in the sample of the element has a mass of 20.18 amu. Explain with reason.
• Define orbital. Why the energy of antibonding molecular orbital is higher than corresponding bonding molecular orbitals?
• State Heisenberg’s Uncertainty Principle and give its mathematical expression.
• Distribute tk electron in orbitals of 29Cu and 26Fe. OR Justify that the distance gaps between different orbitals go on increasing from the lower to higher orbits.
• State the Hess’s law of constant heat summation. OR Give statement of Hess’s law.
• Sketch the molecular orbital picture of 02. OR Define Hydrogen Bonding.
• Write two applications of equilibribm constant.
• Define pH and p0H.
• Water and ethanol can mix in all proportions, give reason. OR What is water of crystallization? Give two examples.
• One mg of K2CrO4 has thrice the number of ions than the number of formula units when ionized in water, justify.
• One molal solution of urea in water is dilute as compared to one molar solution of urea but the number of particles bf solute is same. Justify it
• What is ionic product of water? Define pH.
• Gasoline evaporates much faster than water. Give reason.
• The vapour pressure of diethyl ether is higher than that of water at same temperature. Give reason.
• Water vapours do not behave ideally at 273 K. Justify.
• Water vapours do not behave ideally at 273 K. Explain
• What is meant by water of crystallization? Give an example. .
• Differentiate between adsorption chromatography and partition chromatography.
• How many molecules of water are there in lOg of ice? OR Ice occupies more space than water, give reason.
• Define and write the meaning of chromatography.
• What do you know about Rf value of a component in paper chromatography?
• Define chromatography. Give, its two uses. OR Differentiate between stationary and mobile phase used in chromatography.
• Define sublimation. What type of a substance can be purified by this technique?
• Give the importance of sublimation. OR Define sublimation and partition law.
• Heat of sublimation of iodine is very high although it is a molecular solid. Give reason.
• What is sublimation? Give one example of sublime solid.
• State Boyle’s law of gases.
• Give two applications of plasma.
• How the percentage ionic character of a covalent bond is determined by dipole moment?
• What is plasma state? How is plasma formed at high temperature?
• Ionic solids do not conduct electricity in solid state. Give reason.
• How the electronegativity difference of two bonded atom can be used to predict the ionic/covalent nature of the bond
• No bond in chemistry is 100% ionic. Justify it. OR Why ionic crystals are highly brittle?
• Why the ionic radius of Cf- ion increases from 99 pm to 181 pm?
• Ionic crystals are highly brittle. Explain with reason.
• Differentiate between ideal and non-ideal solutions.
• Many solutions do not behave ideally. Give reason.
• Calculate the molarity of a solution containing 9 grams of glucose (C61-11206) in 250 cm3 of solution.
• Define molal boiling constant with an example.
• One molal solution of glucose is dilute as compared to one molar solution of glucose. Justify it. OR What is molarity?
• Salt bridge is not required in lead storage call. Why?
• Write down reactions taking place at the electrodes on the discharging of Nickle-Cadmium Cell.
• What is the function of salt bridge in galvanic cell?
• Calculate the oxidation number of Cr in K2CrO4 and Cr202-2.
• Find out the oxidation state of Mn in (a) KMnO4 (ii) K2MnO4. OR Calculate oxidation number of chromium in CrCt3.
• What is poisoning of a catalyst? Give an example. OR How a catalyst is specific in its action?
• Calculate the oxidation number of `Mn’ in KMnO4.
• Define and give an example of the process of activation of a catalyst.
• N2 and CO have same number of electrons, protons and neutrons. Justify.
• Separate the following molecules as polar or non-polar: (i) CO2 (ii) CH3OH (iii) CC Q4 (iv) HF
• Why N2 and CO have the same number of protons, electrons and neutrons?
• Define the term molecule. Give two examples also.