Explore topic-wise InterviewSolutions in .

Element P, Q, R and S belong to the same group. The oxide of P is acidic, oxide of Q and R are amphoteric while the oxide of S is basic. Which of the following elements is the most electropositive ?

During photosynthesis, the light energy is converted to chemical energy that is later used by the green plants for their activities. This is an example of ________________ reaction.

Give the formulae of the chlorides of the elements X and Y having atomic numbers of 3 and 6 respectively.
Will the properties of the two chlorides be similar or different? Explain your answer.

Balance the following equations:
1. FeCl₃ + NH₄OH → Fe(OH)₃ + NH₄Cl
2. Na₂S₂O₃ + I₂ → Na₂S₄O₆ + NaI

Manganese is a transition element because _____________.

Are all metal carbonates and metal hydrogencarbonates basic in nature? Explain

Which of the following is the correct representation of carbon tetrachloride($CC{l}_4$)?

Which is the most reactive nonmetal?

How does the method used for extracting a metal from its ore depend on the metal's position in the reactivity series? Explain with examples.

Question 24
Verify by calculating that

(a) 5 moles of $C{O}_2$ and 5 moles of $H_{2}O$ do not have the same mass.

(b) 240 g calcium and 240 g magnesium elements have a mole ratio of 3:5.

Complete the following reaction:

$nC{H}_2=C{H}_2\underset{Highpressure,Catalyst}{\overset{HighTemperature}{\to }}$

What percentage of the solar energy is trapped and utilised by the plants?

Dimethyl ether is an isomer of ethanol.

Why is it wrong to write that "antioxidants REDUCE OXYGEN"?

Three elements 'X', 'Y' , 'Z' having atomic number 11, 7 , 6 respectively react with oxygen to form their iroxides .

Arrange these oxides in increasing order of their basic nature.

Boron generally forms:

We often use this fuel to keep our houses cool or warm.

Choose the correct option:

A certain quantity of a gas occupies a volume of 1000 $c{m}^3$ at 760 mm and ${27}^{\circ }C$. Find the volume of the gas if the pressure and temperature are 1520 mm and ${327}^{\circ }C$.

Plaster of Paris is prepared by heating which of the following compounds?

Which of the following are used as an indicator for identifying acids and bases:

Elements having 5 valence electrons are placed in____.

The acid present in tomato is:

Calculate the mass of 10²² atoms of sulphur.

[Atomic mass: S = 32, C = 12 and O=16 and Avogadro's Number = 6 x 10²³]

Match the following symbols to their corresponding physical states:

$$\begin{array}{cc}PhysicalState& Symbol\\ Gas& \left(A\right)\left(dw\right)\\ Solid& \left(B\right)\left(g\right)\\ Liquid& \left(C\right)\left(aq\right)\\ Dissolvedinwater\left(solutionwithwater\right)& \left(D\right)\left(l\right)\\ & \left(E\right)\left(s\right)\\ & \left(F\right)\left(v\right)\end{array}$$

What type of bonding would you expect between the following pairs of elements?
(i) Calcium and Oxygen
(ii) Carbon and Chlorine
(iii) Hydrogen and Chlorine

Name the process in which a harmful chemical enters the food chain and gets concentrated at each trophic level.

Complete and balance the following chemical equations :

(a) $Zn\left(s\right)+HCl\left(aq\right)\to$

(b) $N{a}_{2}C{O}_3\left(s\right)+HCl\left(aq\right)\to$

(c) $NaHC{O}_3\left(s\right)+HCl\left(aq\right)\to$

(d) $NaOH\left(aq\right)+HCl\left(aq\right)\to$

(e) $CuO\left(s\right)+HCl\left(aq\right)\to$

Which of the following cannot be added in a composting pit to prepare compost?

(a) sunflower (b) fruit and vegetable peels

(c) flowers of plastic (d) red worms

If the energy available at the producer level in a food chain is 150 J, how much energy will be transferred to the tertiary consumer?

(a) 15 J (b) 10 J (c) 1.50 J (d) 0.15 J

How to count the oxidation number of NH₄⁺ N₂H₄ NH₂OH and N₂O?

$MgS{O}_4.H_{2}O$ is also known as

(a) What is meant by biodegradable waste materials? Give two examples of biodegradable wastes.

(b) Which of the following materials are non-biodegradable? Aluminium wire, Tea leaves, Synthetic fibre, Wool

Classify bases on the basis of their concentration, acidity and ionisation. Explain with examples in case.

How we can prove metallic oxides are basic and non- metallic oxides are acidic?

If both ore and gangue contain sulphur then ___ is used to separate ore from gangue in the froth flotation process.

Electromagnetic radiations of wavelength 242 nm is just sufficient to ionize Sodium atom. Then the ionization energy of Sodium in kJ mole⁻¹ is

300 ml of a gas at ${27}^{\circ }$ C is cooled to - $3^{\circ }$ C at constant pressure, the final volume is

A substance X is a compound of an element of group 1, and gives violet colour in flame test. X is:

Relatively more volatile substance among the following

The non-metals are present:

The process by which metals become more resistant to wear and tear by freezing them to low temperatures is known as

Read the following passage and answer the question at the end of it.

The mixing of different gases by random molecular motion and with frequent collisions is called diffusion. A similar process in which gas molecules escape without collision through a tiny hole into a vacuum is called effusion.

1. Select the correct alternate(s).

(a) All gases spontaneously diffuse into one another when they are brought into contact.

(b) Diffusion into a vacuum will take place much more rapidly than diffusion into another gas.

(c) Both the rate of diffusion of a gas and its rate of effusion depend on its molar mass.

(d)All of the above statements are correct

2. The stopcock of the bulbs X (containing $N{H}_3$ and Y (containing HCl) are opened simultaneously. White fumes of $N{H}_{4}Cl$ are formed at point B. If AB = 36.5 cm, then BC is approximately

What happens when sodium sulphite reacts with sulphuric acid?