List of top Science Questions

Which of the following hydrocarbons undergo addition reactions: C2H6 , C3H8 , C3H6 , C2H2 and CH4 .

What change will you observe if you test soap with litmus paper (red and blue)?

Explain the formation of scum when hard water is treated with soap.

Why are carbon and its compounds used as fuels for most applications?

Why does micelle formation take place when soap is added to water? Will a micelle be formed in other solvents such as ethanol also?

Which of the following terms does not represent electrical power in a circuit?
A piece of wire of resistance R is cut into five equal parts. These parts are then connected in parallel. If the equivalent resistance of this combination is R′, then the ratio \(\frac {R}{R^′}\) is –

How can ethanol and ethanoic acid be differentiated on the basis of their physical and chemical properties?

What is an homologous series? Explain with an example.

Draw the electron dot structures for 
(a) ethanoic acid. 
(b) H2S. 
(c) propanone. 
(d) F2

Explain the nature of the covalent bond using the bond formation in CH3Cl.

While cooking, if the bottom of the vessel is getting blackened on the outside, it means that

Ethane, with the molecular formula C2H6 has

What is biological magnification? Will the levels of this magnification be different at different levels of the ecosystem?
Will the impact of removing all the organisms in a trophic level be different for different trophic levels? Can the organisms of any trophic level be removed without causing any damage to the ecosystem?
What will happen if we kill all the organisms in one trophic level?
Which of the following are environment-friendly practices?
Which of the following constitute a food-chain?
Which of the following groups contain only biodegradable items?

Give two important uses of washing soda and baking soda.

What is a neutralization reaction? Give two examples.

Plaster of Paris should be stored in a moisture-proof container. Explain why?

What is the function of an earth wire? Why is it necessary to earth metallic appliances?

Fresh milk has a pH of 6. How do you think the pH will change as it turns into curd? Explain your answer.

Equal lengths of magnesium ribbons are taken in test tubes A and B. Hydrochloric acid (HCl) is added to test tube A, while acetic acid (CH3COOH) is added to test tube B. Amount and the concentration taken for both the acids are the same. In which test tube will the fizzing occur more vigorously and why?