Niharika Rana

What do you mean by equilibrium state?

Chemicalequilibriumrefers to thestateof a systeminwhich the concentration of the reactant and the concentration of the products do not change with time and the system does not display any further changeinproperties.

The solubility product constant of Ca(OH)2 at 25°C is 4.42 x 10-5. A 500 mL of a saturated solution of Ca(OH)2 is mixed with an equal volume of 0.4 M NaOH. What mass of Ca(OH)2 is precipitated out?

Let the solubility of $C a (O H)_{2}$ in pure water
= S moles/litre
$C a (O H)_{2} C a^{2 +} + 2 O H$
S 2S
$T h e n K_{s p} = [C a^{2 +}] [O H]$
$4.42 10^{5} = S (2 S)^{2}$
$4.42 10^{5} = 4 S^{3}$
$S = 2.224 10^{2} = 0.0223 m o l e s l i t r e^{1}$
No. of moles of $C a^{2 +}$ ions in 500 ml of solutions = 0.011. Now when 500 ml of saturated solution is mixed with 500 ml of 0.4 M NaOH, the resultant volume is 1000 ml. The molarity of $O H$ ions on the resultant solution would therefore be 0.2 M
Maximum $[C a^{2 +}]$ that can be tolerated $= \frac{k s p}{{[O H]}^{2}}$
$= \frac{4.42 10^{5}}{(0.2)^{2}} = 0.0011 M$
Thus number of moles of $C a^{2 +}$ or $C a (O H)_{2}$ precipitated...

If the volume of 25 cm3 of 0.05 M Ba(NO3)2 are mixed with 25 cm3 of 0.02 M NaF. Will any BaF2 precipitate? [Ksp of BaF2 = 1.7 x 10-6 at 298K]

Number of moles of NaF in 25.0 cm^3

0.02 /1000 * 25.0 = 5.0 x 10^-4

The total volume of the solution on mixing Ba(NO3)2 and NaF solutions

= 25.0 + 25.0

= 50.0cm^3

This means that 1.25 10^-3 moles of Ba(NO3) and 5.0 10^-4 moles of NaF are now present in 50cm3

.: The concentration of Ba(NO3)2 in solution

(1.25 10^-3 )/50 x 1000

= 0.025 mol L^-1

and, the concentration of NaF in solutions

= (5.0x 10^-4)/50x 1000

= 0.01 mol L^-1

Hence, | Ba?+| = | Ba(NO3)2] in solution

= 0.025 x (0.01)^2

= 2.5 x 10^-6

The...

What will be the resultant pH when 200 mL of an aqueous solution of HCl (pH = 2) is mixed with 300 mL of an aqueous solution of NaOH (pH = 12)?

Since, according to the question;

200 ml of an aqueous solution of HCl is mixed with 300 ml of an aqueous solution of NaOH.

The given pH of HCl is 2;

The given pH of NaOH is 12;

We have to find the resultant pH.

[HCl] =

[NaOH] =

So, the reaction goes like this :

Since , before reaction;

After reaction;

0 1 2 2

We will be finding the concentration of the hudroxide ion first.

left from NaOH =M

The Ph of the hydroxide ion is calculated as

Since , we know that

Theof the hydrogen ion...

How is a strong electrolyte different from a weak electrolyte?

The main difference between strong electrolytes and weak electrolytes is thatstrong electrolytes can almost completely dissociate into its ionswhereas weak electrolytes partially dissociate into ions.

Write a concise account of the solubility product principle.

The solubility productconstant istheequilibrium constant forthedissolutionof asolid substance into an aqueous solution. It is denoted bythesymbol Ksp.The solubility productisakindofequilibrium constant and its value depends on temperature. Ksp usually increases with an increase in temperature due to increasedsolubility.