Assertion : One mole of NaCl contains 6.023 $\times$ 10²³ molecules of sodium chloride.

Reason : 58.5 g of NaCl also contains 6.023 x 10²³ molecules of NaCl.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false

• If both assertion and reason are false.

Assertion : For Balmer series of hydrogen spectrum, the value n₁ = 2 and n₂ = 3, 4, 5... .

Reason : The value of n₂ for a line in Balmer series of hydrogen spectrum having the highest wavelength is 6.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Isopropylbenzene on air oxidation in the presence of dilute acid gives

• C₆H₅COOH

• C₆H₅COCH₃

• C₆H₅CHO

• C₆H₅OH

Lassaigne's test for the detection of nitrogen fails in

• H₂N-CO-NHNH₂.HCl

• NH₂-NH₂.HCl

• C₆H₅-NH-NH₂.HCl

• C₆H₅CONH₂

Which of the following is not a greenhouse gas?

• Carbon dioxide

• Water vapours

• Methane

• Oxygen

Which of the following has highest hydration energy?

• MgCl₂

• CaCl₂

• BaCl₂

• SrCl₂

17.

Which of the following is aromatic?

• 

• 

• 

• 

Which of the following reactions produces hydrogen?

• Mg + H₂O

• H₂S₂O₈ + H₂O

• BaO₂ + HCl

• Na₂O₂ + 2HCl

Addition of group-13 elements to intrinsic semiconductors results in

• creation of conduction band slightly above the valence band

• creation of conduction band slightly below the valence band

• creation of valence band slightly above the conduction band.

• overlapping of valence band and conduction band

Which of the following elements will have the highest electron affinity ?

• Chlorine

• Nitrogen

• Phosphorus

• Fluorine