21575.Hydroxyl ion concentration of 1M HCl is
1 × 10–14 mol dm–3
1 × 10–1 mol dm–3
1 × 10–13 mol dm–3
1 × 101 mol dm–3
21576.Solid Ba(NO3)2 is gradually dissolved in a 1.0 × 10–4 M Na2CO3 solution. At what concentration of Ba2+ will a precipitate begin to form? (Ksp for BaCO3 = 5.1 × 10–9)
5.1 × 10–5 M
8.1 × 10–8 M
8.1 × 10–7 M
4.1 × 10–5 M
21577.If, in the reaction N2O4 ⇌ 2NO2, $x$ is that part of N2O4 which dissociates, then the number of molecules at equilibrium will be
1
3
(1 + $x$)
(1 + $x$)2
21578.The solubility of Ca3(PO4)2 in water is y moles/litre. Its solubility product is
6y4
36y4
64y5
108y5
21579.Consider the following gaseous equilibria with equilibrium constants K1 and K2 respectively.
SO2(g) + $\dfrac{1}{2}$O2(g) ⇌ SO3(g)
2SO3(g) ⇌ 2SO2(g) + O2(g)
The equilibrium constants are related as ______.
2K1 = K2
2
2
K2
1 = $\dfrac{1}{\text{K}_2}$
1 = $\dfrac{1}{\text{K}_2}$
K2
2 = $\dfrac{1}{\text{K}_1}$
2 = $\dfrac{1}{\text{K}_1}$
K2 = $\dfrac{1}{\text{K}_1^2}$
21580.Three reactions involving H2PO–
4 are given below:
4 are given below:
(i) H3PO4 + H2O → H3O+ + H2PO–
4
(ii) H2PO–
4 + H2O → HPO2–
4 + H3O+
(iii) H2PO–
4 + OH– → H3PO4 + O2+
In which of the above does H2PO–
4 act as an acid?
(i) only
(ii) only
(i) and (ii)
(iii) only
21581.Solubility product of silver bromide is 5.0 × 10–13. The quantity of potassium bromide (molar mass taken as 120 g mol–1) to be added to 1 litre of 0.05 M solution of silver nitrate to start the precipitation of AgBr is
5.0 × 10–8 g
1.2 × 10–10 g
1.2 × 10–9 g
6.2 × 10–5 g
21582.One dm3 solution containing 10–5 moles each of Cl– ions and CrO4–2 ions is treated with 10–4 mole of silver nitrate. Which one of the following observations is made?
[KSP of Ag2CrO4 = 4 × 10–12]
[KSP of AgCl = 1 × 10–10]
Silver chromate gets precipitated first.
Precipitation does not occur.
Both silver chromate and silver chloride start precipitating simultaneously.
Silver chloride gets precipitated first.
21583.The first and second dissociation constants of an acid H2A are 1.0 × 10–5 and 5.0 × 10–10 respectively.The overall dissociation constant of the acid will be
5.0 × 10–5
5.0 × 1015
5.0 × 10–15
0.0 × 105
21584.pH value of which one of the following is NOT equal to one?
0.1 M CH3COOH
0.1 M HNO3
0.05 M H2SO4
50 cm3 0.4 M HCl + 50 cm3 0.2 M NaOH