Most Asked Short Questions Of Chemistry
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Language Of Chemistry
1. What is meant by the term basicity? Predict the basicity of H2SO4 in the following reaction.
2. Define a chemical change and point out its two importance characters.
3. How many electrons and neutrons are present in the symbol Al ?
4. What information can you obtain from the symbol K?
Chemical Arithmetic
Dalton's Atomic Theory and Laws of Stoichiometry
1. Why is the law of reciprocal proportion called the law of equivalent proportion?
2. How does Dalton's atomic theory explain the law of conservation of mass?
3. State the law of definite proportion and give an example to support this law.
4. State law of Reciprocal proportion.
5. State law of multiple proportions.
6. 12 g of carbon react with 32 g of oxygen to produce 44 g of carbon dioxide. Which chemical law do these data illustrate? State the law.
7. State the law of conservation of mass. Why is this law known as law of indestructibility of matter?
8. One volume of hydrogen reacts with one volume of chlorine to give two volume hydrogen chloride gas. Which law of stoichiometry is illustrate? State the law.
9. How did the law of multiple proportions encourage Dalton's to introduce an atomic theory?
Atomic Mass and Molecules Mass
1. How many number of moles of CO will be left when 2 * 10^21 molecules are removed from 0.28 g of CO?
2. Calculate mass in gram of
i) two atom of carbon
ii) three molecules of hydrogen.
3. How many grams of sulphur and oxygen are needed to produce 6.023 * 10^24 molecules of SO2 according to the reaction?
4. How many number of oxygen molecules are required to produce 220 mg of CO2 according to the reaction?
5. Calculate the mass of carbon monoxide having the same number of oxygen atoms as are present in 88 g of carbon dioxide.
Empiricel, Molecules Formula And Limiting Reactants
1. What is a limiting reactant? Why is it essential in stoichiometry calculations?
Avogadro's Hypothesis & Its Application
1. Calculate the wt. of 11.2 litres of CO2 gas at STP (molecular weight of CO2 = 44).
2. In what way has Avogadro's Hypothesis given support to Dalton's atomic theory?
Equivalent Masse
1. Calculate the equivalent weight of underline elements:
i) Fe2 O3
ii) MgCl2
iii) CH4
iv) NH3
(given that atomic weight of Fe = 56)
2. 4 g of a divalent metal reacts with chlorine to produce 11.1 g of its metal chloride. Calculate the atomic mass of metal.
3. Define equivalent weight of an element. A divalent metal has atomic weight 24. What is its equivalent weight?
4. Why is hydrogen displacement method not applicable to determine the equivalent mass of copper?
State Of Matter
Gaseous State
1. State Dalton's law of partial pressure.
2. What is an ideal gas? Under what conditions will a gas behave nearly like an ideal gas?
3. Give reason: Gases do not settle at the bottom of the vessel.
4. On the basis of Boyle's law, explain why mountaineers carry oxygen cylinders with them.
5. At what condition the value of P * V is always contact?
Liquid State
1. Cooling is caused by evaporation. Give reason.
2. Define surface tension and write its unit.
3. At what condition does a liquid boil? Point out the effect of increasing temperature on boiling point of liquid.
4. Differentiate between evaporation and boiling.
5. Does atmosphere pressure affect boiling point of liquid? Explain.
6. Define the terms:
i) Aqueous tension
ii) Surface tension
7. Does temperature of boiling liquid increase, decrease or remain constant even though the heat is continued? give reason.
8. Give reason:
i) It is more efficient to wash clothes in hot water than cold water
ii) Evaporation takes place from the surface of the liquid.
9. Define the term coefficient of viscosity.
10. What is meant by viscosity?
11. What is evaporation? How does it differ from boiling point?
Solid state
- Define the terms Isotropy and Hygroscopy
- Different between Crystal lattice and Unit cell
- Give reason : Efflorescent substance lose water of crystallization after being exposed to air.
- Give reason : Deliquescent substance turn into liquid when exposed to atmospheric air.
- Different between Efflorescent substance and Deliquescent substance.
- Different between Crystalline solid and Amorphous solid.
Atomic Structure
- Write down the electronic configuration of copper and potassium.
- What is the conclusion made by de-Broglie? write its mathematical relationship .
- Calculate the atomic number and number of p-electrons of an atom whose valence shell electronic configuration is 4s^2 ?
- Which principle goes against the concept of Bohr's fixed orbits? State the principle.
- Write down the electronic configuration of Cu and Cl
- What is meant by quantization of angular momentum?
- What is meant by degenerate orbitals? give example.
- What are the limitations of Bohr's model of atom?
- What is Hund's rule?
- State Pauli-exclusion principle.
- What is an atomic orbital? What are shapes of a S-orbital and P-orbital?
- What is meant by atomic spectrum?
- What is Bohr's-Bury rule?
- For n= 4, write all possible values of L and M