Explore topic-wise InterviewSolutions in .

What will be the atomicity of:

a) the molecule which is consumed during respiration and released during photosynthesis.

b) the red coloured element which is found on the tips of match sticks.

c) the pale blue gas which forms a layer that absorbs the sun's UV radiation.

Burning of coal ______energy.

Question 9
Explain how the painting of an iron gate prevents it from rusting.

Permanent hardness is caused by the dissolved __(sulphates/bicarbonates) of calcium and magnesium.

The most abundant metal in the earth crust is

Photosynthesis is a physical or chemical change; reversible or Irreversible.

Clotting of blood is a physical or chemicalchange; reversible or Irreversible.

Liberation of oxygen occurs in the process of what

Inflation of a balloon is a physical or chemicalchange; reversible or Irreversible

Pick the correct stage of silkworm life cycle as seen in picture

Silk is both extracted and spun into a thread in a single process called

Which theory has provided an explanation for the law of conservation of mass and the law of definite proportions?

Consider a beaker with some quantity of water, as sugar is added to it the pressure at a certain depth ___.

Which of the following is not a property of acids?

If the pH value of a substance is below seven then it is ______ in nature.

In a closed container at a given temperature, concentration of a product P increases from $0.1mol/L$ to $0.5mol/L$ in $10min$

Then the average rate of reaction in first $10min$ will be:

Question 14

Match the items of Column I with the items of Column II.

Soil is made up of other things in addition to rock particles. Other than rock particles, soil contains________.

NGO which works for the welfare of people living in villages observed a few situations in a village and its surrounding areas. Which of these observations according to you signifies water scarcity?

Question 2

How does the atmosphere act as a blanket?

At what time of the day should we water the plants in a garden?

Which of the following is the main cause of increased percentage of carbon dioxide in the atmosphere?

Metals that melt in our hand are:

Why does all the oxygen of atmosphere not get used up?

In India many people do not have the access to safe drinking water, what appears safe is just clear water. So what is safe drinking water according to you?

Why do we need to balance a chemical reaction?

Question 13

State whether the following statements are true or false.

(a) A mixture of oil and water can be separated by filtration.
(b) Water can be separated from salt by evaporation.
(c) A mixture of wheat grains and wheat flour can be separated by sieving.
(d) A mixture of iron filings and rice flour can be separated by magnet.
(e) A mixture of wheat grains and rice flakes can be separated by winnowing.
(f) A mixture of tea leaves and milk can be separated by decantation.

Why turmeric paper change it's colour when I pour a base?

The temperature coefficient of the EMF of the cell is given by:

A radio nuclide with half life T days emits $\beta$-particles of average kinetic energy E joule . This radionuclide is used as source in a machine which generates electric energy with efficiency $\eta$. The no.of moles of the nuclide required to generate electrical energy at an initial rate P is ( Avagadro no. =N)

Which of the following are physical changes ?

(i) melting of iron metal (ii) rusting of iron metal

(iii) bending of an iron rod (iv) drawing a wire of iron metal

(a) (i), (ii) and (iii) (b) (i), (ii) and (iv) (c) (i), (iii) and (iv) (d) (ii) (iii) and (iv)

When lemon juice falls on a marble kitchen counter, which is the gas that bubbles out?

In a reaction carried out at 400 K, 0.01% of the total number of collisions is effective. The energy of activation of the reaction is