What is the total number of moles of H₂SO₄ needed to prepare 5.0 L at a 2.0M solution of H₂SO₄ ?

• 2.5

• 5.0

• 10

• 20

Which combination of atoms can form a polar covalent bond ?

• H and N

• H and Br

• N and N

• Na and Br

How many joules of heat are absorbed when 70.0 g of water is completely vaporised at its boiling point ?

• 23, 352

• 7,000

• 15,813

• 158, 130

14.

In any chemical reaction, a quantity that decrease to a minimum is

• free energy

• entropy

• temperature

• enthalpy

The pH of 10^-8 M NaOH aqueous solution at 25°C, is

• 7.02

• 7.0

• 6.89

• 6.0

Decrease in atomic number is not observed during

• β- emission

• α- emission

• positron emission

• electron capture

The buffering action of an acidic buffer is maximum when its pH is equal to

• 5

• 7

• 1

• pK_a

Which of the following will increase with the increase in temperature ?

• Surface tension

• Viscosity

• Molality

• Vapour pressure

Geometry of methyl free radical is

• pyramidal

• planar

• tetrahedral

• linear

The electron configuration of the oxide ion is much most similar to the electron configuration of the

• sulphide ion

• nitride ion

• oxygen atom

• nitrogen atom