The solution would need 13.9 g of KCl
0.75 m, means molal concentration
0.75 moles in 1 kg of solvent.
Let's think as an aqueous solution.
250 mL = 250 g, cause water density (1g/mL)
1000 g have 0.75 moles of solute
250 g will have (0.75 . 250)/1000 = 0.1875 moles of KCl
Let's convert that moles in mass (mol . molar mass)
0.1875 m . 74.55 g/m = 13.9 g
Ammonia (NH₃) shows basic character in aqueous solution:
NH₃ + H₂O ⇄ NH₄⁺ + OH⁻. This is basic buffer, because contains hydroxide anions.
Ammonium chloride is salt and in water dissociate:
NH₄Cl → NH₄⁺ + Cl⁻.
Ammonium ion shows acidic character in aqueous solution::
NH₄⁺ + H₂O ⇄ NH₃ + H₃O⁺.
Ka = [NH₃] · [H₃O⁺] ÷ [NH₄⁺].
KHT is a salt which ionises in water as follows
KHT ⇄ K⁺ + HT⁻
Solubility product Kw= [ K⁺ ] [ HT⁻ ]
product of concentration of K⁺ and HT⁻ in water
In KCl solution , the solubility product of KHT will be decreased .
In KCl solution , there is already presence of K⁺ ion in the solution . So
in the equation
[ K⁺ ] [ HT⁻ ] = constant
when K⁺ increases [ HT⁻ ] decreases . Hence less of KHT dissociates due to which its solubility decreases . It is called common ion effect . It is so because here the presence of common ion that is K⁺ in both salt to be dissolved and in solvent , results in decrease of solubility of the salt .
- Elements of the the same group have similar number of valence electrons.
- They have identical number of electrons in their outermost shell. For example ; All the alkali metals in Group 1 have 1 valence electron.
And so many more.
Due to all these similarities ,they have similar properties and they tend to react similarly with other substances.