_ZX^M + ₂He⁴ → ₁₅P³⁰ + ₀n¹. Then

• Z = 12, M = 27

• Z = 13, M = 27

• Z = 12, M = 17

• Z = 13, M = 28

Which expression has no physical significance?

• ${\left(\frac{\partial \mathrm{G}}{\partial \mathrm{T}}\right)}_{\mathrm{p}}$

• ${\left(\frac{\partial \mathrm{G}}{\partial \mathrm{p}}\right)}_{\mathrm{T}}$

• ${\left(\frac{\partial (∆\mathrm{G})}{\partial \mathrm{T}}\right)}_{\mathrm{p}}$

• ${\left(\frac{\partial (∆\mathrm{G})}{\partial \mathrm{p}}\right)}_{\mathrm{T}}$

Heat of neutralisation of weak acid and strong base is less than the heat of neutralisation of strong acid and strong base due to

• energy has to be spent for the total dissociation of weak acid

• salt of weak acid and strong base is not stable

• incomplete dissociation of weak acid

• incomplete neutralisation of weak acid

A colourless crystalline salt 'x' is soluble in dilute HCl. On adding NaOH solution, it gives a white precipitate which is insoluble in excess of NaOH. 'x' is

• Al₂(SO₄)₃

• ZnSO₄

• MgSO₄

• SnCl₂

The chemical equilibrium of a reversible reaction is not influenced by

• pressure

• catalyst

• concentration of the reaction

• temperature

56g of nitrogen and 8g of hydrogen gas are heated in a closed vessel. At equilibrium 34 g of ammonia are present. The equilibrium number of moles of nitrogen,hydrogen and ammonia respectively are

• 1,2,2

• 2,2,1

• 1,1,2

• 2,1,2

Solubility product of a salt AB is 1 × 10^-8 in a solution in which concentration of A is 10^-3 M. The salt will precipitate when the concentration of B becomes more than

• 10^-4 M

• 10^-7 M

• 10^-6 M

• 10^-5 M

In a mixture of acetic acid and sodium acetate the ratio of concentrations of the salt to the acid is increased ten times. Then the pH of the solution

• increases by one

• decreases by one

• decreases ten fold

• increases ten fold

In a lime kiln to get higher yield of CO₂, the measure that can be taken is

• to remove

• to add more CaCO₃

• to mamtain high temperature

• to pump out CO₂

15 moles of H₂ and 5.2 moles of I₂ are mixed and allowed to attain equilibrium at 500°C. At equilibrium, the concentration of HI is found to be 10 moles. The equilibrium constant for the formation of HI is

• 50

• 15

• 100

• 25