2. Acids such as HCI, HNOstep three are almost completely? onised and hence they have high Ka value i.e., Ka for HCI at 25°C is 2 x ten 6 .
cuatro. Acids with Ka value greater than ten are considered as strong acids and less than one considered as weak acids.
- HClO4, HCI, H2SO4 – are strong acids
- NH2 – , O 2- , H – – are strong bases
- HNO2, HF, CH3COOH are weak acids
Question 5. pH of a neutral solution is equal to 7. Prove it. in neutral solutions, the concentration of [H3O + ] as well as [OH – ] are equal to 1 x 10 -7 M at 25°C.
2. The pH of a neutral solution can be calculated by substituting this [H3O + ] concentration in the expression pH = – log10 [H3O + ] = – log10 [1 x 10 -7 ] = – ( – 7)log \(\frac < 1>< 2>\) = + 7 (l) = 7
Answer: 1
Question 7. When the dilution increases by 100 times, the dissociation increases by 10 times. Justify this statement. Answer: (i). Let us consideran acid with Ka value 4 x 10 4 . We are calculating the degree of dissociation of that acid at two different concentration 1 x 10 -2 M and 1 x 10 -4 M using Ostwalds dilution law
(wev) we.age., in the event the dilution develops from the a hundred moments (quantity decreases from 1 x 10 -dos Meters to just one x ten -4 Yards), the brand new dissociation increases from the ten moments.
- Boundary try a remedy having its a combination of weakened acidic and its conjugate legs (or) a failure base and its own conjugate acid.
- It barrier services resists extreme changes in their pH through to inclusion from a little levels of acids (or) basics and escort services in Pembroke Pines this element is named buffer step.
- Acidic buffer solution, Solution containing acetic acid and sodium acetate. Basic buffer solution, Solution containing NH4O and NH4Cl.
- The new buffering feature out-of a remedy is going to be mentioned when it comes off boundary capacity.
- Shield directory ?, just like the a decimal way of measuring the brand new barrier strength.
- It is recognized as just how many gram competitors out-of acidic otherwise ft put into step one litre of one’s boundary option to alter its pH by unity.
- ? = \(\frac < dB>< d(pH)>\). dB = number of gram equivalents of acid / base added to one litre of buffer solution. d(pH) = The change in the pH after the addition of acid / base.
Matter ten. How was solubility device is accustomed decide brand new precipitation from ions? If equipment away from molar intensity of the brand new component ions i.age., ionic product exceeds new solubility tool then the material will get precipitated.
2. When the ionic Product > Ksp precipitation will occur and the solution is super saturated. ionic Product < Ksp no precipitation and the solution is unsaturated. ionic Product = Ksp equilibrium exist and the solution ?s saturated.
3. From this way, the fresh solubility product discovers useful to pick whether a keen ionic material gets precipitated when solution that contain the component ions is combined.
Matter 11. Solubility should be determined away from molar solubility.we.elizabeth., the most level of moles of the solute that can be mixed in a single litre of your own service.
3. From the above stoichiometrically balanced equation, it is clear that I mole of Xm Yn(s) dissociated to furnish ‘m’ moles of x and ‘n’ moles of Y. If’s’ is the molar solubility of Xm Ynthen Answer: [X n+ ] = ms and [Y m- ] = ns Ksp = [X n+ ] m [Y m- ] n Ksp = (ms) m (ns) n Ksp = (m) m (n) n (s) m+n