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List three distinguishing features, in tabular form, between acquired traits and the inherited traits.
Concept: Organic Evolution
What is meant by a power of a lens? Define its SI unit.
Concept: Power of a Lens
Write the function of the following part of the human eye: Cornea
Concept: Human Eye
Write the function of the following part of the human eye: crystalline lens
Concept: Human Eye
Write the function of the following part of the human eye: ciliary muscles
Concept: Human Eye
Draw the well-labelled diagram of the human excretory system
Concept: Excretion
Draw the well-labelled diagram of the human excretory system
Concept: Excretion
What is atmospheric refraction? Use this phenomenon to explain the following natural events:
Twinkling of stars
Draw diagrams to illustrate your answers.
Concept: Atmospheric Refraction
Write Joule's law of heating.
Concept: Effects of Electric Current >> Heating Effect of Electric Current
What is the Principle of an Electric motor?
Concept: Electric Motor
Decomposition reactions require energy either in the form of heat or light or electricity for breaking down the reactants. Write one equation each for decomposition reactions where energy is supplied in the form of heat, light and electricity
Concept: Types of Chemical Change or Chemical Reaction >> Decomposition Reactions
2 mL of sodium hydroxide solution is added to a few pieces of granulated zinc metal taken in a test tube. When the contents are warmed, a gas evolves which is bubbled through a soap solution before testing. Write the equation of the chemical reaction involved and the test to detect the gas. Name the gas which will be evolved when the same metal reacts with dilute solution of a strong acid.
Concept: Chemical Equation
What is observed when a solution of sodium sulphate is added to a solution of barium chloride taken in a test tube? Write equation for the chemical reaction involved and name the type of reaction in this case.
Concept: Types of Chemical Change or Chemical Reaction >> Double Displacement Reaction
The pH of a salt used to make tasty and crispy pakoras is 14. Identify the salt and write a chemical equation for its formation. List its two uses.
Concept: Salts
Why are most carbon compounds poor conductors of electricity?
Concept: The Covalent Bond
Write the steps involved in the extraction of pure metals in the middle of the activity series from their carbonate ores.
Concept: Extraction of Reactive Metals
How is copper extracted from its sulphide ore? Explain the various steps supported by chemical equations. Draw labelled diagram for the electrolytic refining of copper.
Concept: Extraction of Reactive Metals
A student added few pieces of aluminium metal to two test tubes A and B containing aqueous solutions of iron sulphate and copper sulphate. In the second part of her experiment, she added iron metal to another test tubes C and D containing aqueous solutions of aluminium sulphate and copper sulphate.
In which test tube or test tubes will she observe colour change? On the basis of this experiment, state which one is the most reactive metal and why.
Concept: Physical Properties of Metals
A compound 'X' on heating with excess conc. sulphuric acid at 443 K gives an unsaturated compound 'Y'. 'X' also reacts with sodium metal to evolve a colourless gas 'Z'. Identify 'X', 'Y' and 'Z'. Write the equation of the chemical reaction of formation of 'Y' and also write the role of sulphuric acid in the reaction.
Concept: Saturated and Unsaturated Carbon Compounds
Why are most carbon compounds poor conductors of electricity?
Concept: The Covalent Bond
