Chemistry, 22.04.2020 03:29 robbylynnbonner

Which of the following solutions is a good buffer system?Which of the following solutions is a good buffer system?A solution that is 0.10 M Li OH and 0.10 MHNO3A solution that is 0.10 MHCN and 0.10 MLiCNA solution that is 0.10 MNaCl and 0.10 MHClA solution that is 0.10 M Li and 0.10 MHNO3A solution that is 0.10 MHCN and 0.10 M Li Cl

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Answer from: mia2286

A solution that is 0.10 M HCN and 0.10 M LiCN.

Explanation:

A buffer solution is a solution of a weak acid and its conjugate base or a solution of a weak base and its conjugate acid, so the pH of the solution changes in a very little range when an acid or base is added to the solution.

Let's evaluate each statement:

(a) A solution that is 0.10 M LiOH and 0.10 M HNO₃

This is not a buffer solution since the HNO₃ is not the acid conjugate of the LiOH, and also, the LiOH is a strong base and the HNO₃ is a strong acid.

(b) A solution that is 0.10 M HCN and 0.10 M LiCN

This is a buffer solution, with the following reaction:

HCN + H₂O ⇄ CN⁻Li⁺ + H₃O⁺

The acid HCN is a weak acid and the LiCN is its conjugate base. The fact that the concentrations are equal for both is appropriate for the buffer solution.

This is not a buffer solution since the HCl is a strong acid. It dissociates in water to form Cl⁻ and H⁺.

(d) A solution that is 0.10 M Li and 0.10 M HNO₃

This is not a buffer solution since the HNO₃ is not the conjugate base of Li, the HNO₃ is a strong acid that dissociates in water to form H⁺ and NO₃⁻.

(e) A solution that is 0.10 M HCN and 0.10 M LiCl

This is not a buffer solution since the LiCl is not the conjugate base of the acid HCN.

Therefore, the correct option is: A solution that is 0.10 M HCN and 0.10 M LiCN.

I hope it helps you!

Answer from: Quest

by cartels in other countries, shipped by air, mail, or land. i cant really see your answer choices : /

Answer from: Quest

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –

6.022

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,

will have a gram-molecular weight of 352g.

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