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Which of the following factor is responsible for Diamond's high melting point?

Explain distillation of coal

Tick True/False against the following statements. ​

(a) Fossil fuels can be made in the laboratory. (T/F)

(b) CNG is more polluting fuel than petrol. (T/F)

(c) Coke is the almost pure form of carbon. (T/F) ​

(d) Coal tar is a mixture of various substances. (T/F)

(e) Kerosene is not a fossil fuel. (T/F)

Elements try to become stable by attaining inert gas configuration. In the ionic compound sodium chloride (NaCl), sodium and chlorine attain stability by losing and gaining an electron respectively. Identify the correct options assuming the above situation.

Match the items given in column I with one or more items given in column II :

$\begin{array}{cc}\text{Column I}& \text{Column II}\\ \text{(i) prevents photosynthesis}& \text{(a) Sewage dumped in river}\\ \text{(ii) Damage ozone layer}& \text{(b) Excess fertiliser in fields}\\ \text{(iii) Produce acid rain}& \text{(c) Carbon dioxide in air}\\ \text{(iv) Kill fish by deoxygenating water}& \text{(d) Dust in air}\\ \text{(v) Causes water borne diseases}& \text{(e) CFCs}\\ \text{(vi) Leads to global warming}& \text{(f) Sulphur dioxide in air}\end{array}$

Name a non-metal which is in the liquid state at room temperature.

A molecule of hydrogen has :

How do non-metals react with oxygen? Explain with suitable examples.

Among the following compounds octet rule is not obeyed by:

What is the observation that can be made when calcium reacts with $H_{2}O$?

100 mL of a water sample contains 0.81g of calcium bicarbonate and 0.73g of magnesium bicarbonate. The hardness of this water sample expressed in terms of ppm of $CaC{O}_3$ is: (molar mass of calcium bicarbonate is 162 g/mol and magnesium bicarbonate is 146 g/mol.

Why is it advised not to wear synthetic clothes while working in laboratory or kitchen? Name four synthetic fibres and mention their uses apart from their usage in clothes. [5 MARKS]

In $Xe{O}_2{F}_2,XeO{F}_4,Xe{F}_4,Xe{F}_6$ the number of lone pair on $Xe$ is respectively

The uses of an element are given in the following points:
1. For bleaching paper and clothes
2. In the manufacture of plastics, acids, pesticides, etc.
3. To kill germs in water

Identify the element.

Some reasons are given regarding the limited use ofH₂as fuel.
I) its calorific value is low.
II) Its availability in free state is less.
III) It is difficult to store.
IV) It is not a clean fuel.
The correct statements are?

A reaction in which exchange of radicals takes place is called ___ reaction.

Which of the following cells have the highest voltage?

air in hill stations feels fresh and clean. why?

When a mild-steel specimen fails in a torsion test fracture looks like

If I is the intensity of absorbed light and C is the concentration of AB for the photochemical process $AB+hV\to AB$,
then the rate of formation of AB is directly proportional to?

Which of these reactions releases hydrogen gas?

The formation of copper oxide from copper in the presence of oxygen is an ____________ reaction.

$2Cu+O_2\to 2CuO$

A suspension is a ___ mixture in which very fine particles of solid are dispersed in any medium.

What is AMPHOTERIC and COLLISION?

Which among the following is the chemical symbol for iron?

Do basic solutions also have $H^{+}$ (aq) ions? If yes, then why are these basic? [2 MARKS]