Advertisements
Advertisements
Question
Answer the following in brief :
The pH of a weak monobasic acid is 3.2 in its 0.02 M solution. Calculate its dissociation constant.
Advertisements
Solution
Given:
pH = 3.2
Concentration Dissociation = 0.02 M
Dissociation constant (Ka) = ?
Calculation:
Ka = `(Calpha^2)/(1 - alpha)`
`alpha = {[H^+]}/C`
pH = −log10[H+]
3.2 = −log10[H+]
−3.2 = log10[H+]
`10^-3.2 = [H^+]`
`6.3 xx 10^-4 = [H^+]`
`alpha = {[H^+]}/C`
= `(6.3 xx 10^-4)/0.02`
= 0.0315
Ka = `(Calpha^2)/(1 - alpha)`
`(0.02 xx (0.0315)^2)/(1 - 0.0315)`
= `(0.02 xx 0.000992)/0.9685`
= `(0.02 xx 9.92 xx 10^-4)/(1)`
= `0.1984 xx 10^-4`
APPEARS IN
RELATED QUESTIONS
The concentration of hydrogen ion in a sample of soft drink is 3.8 × 10–3 M. what is its pH?
Assuming complete dissociation, calculate the pH of the following solution:
0.002 M HBr
Calculate the pH of the following solutions:
0.3 g of Ca(OH)2 dissolved in water to give 500 mL of solution.
Calculate the pH of the resultant mixtures: 10 mL of 0.2M Ca(OH)2 + 25 mL of 0.1M HCl.
The pH of 10−8 M of HCl is ______.
Answer the following in one sentence:
The pH of a solution is 6.06. Calculate its H+ ion concentration.
Derive the relation pH + pOH = 14.
In NaOH solution [OH–] is 2.87 × 10–4. Calculate the pH of the solution.
Which of the following is INCORRECT statement?
Aqueous solution of ____________ will turn red litmus blue.
pH of a solution is 12. The number H+ ions present in 1 cm3 of this solution is ____________.
50 ml of 0.05 M HNO3 is added to 50 ml of 0.025 M KOH. Calculate the pH of the resultant solution.
The aqueous solution of sugar does not conduct electricity. However, when sodium chloride is added to water, it conducts electricity. How will you explain this statement on the basis of ionisation and how is it affected by concentration of sodium chloride?
Derive the relationship between pH and pOH.
A sample of air turns lime water milky and also turns acidified potassium dichromate green in aqueous solution has low pH. This is due to the presence of pollutants.
Define pOH.
Derive relationship between pH and pOH.
If pH of a solution is 3.12, what would be the concentration of H+ ion?
Derive a relationship between pH and pOH.
Define pOH.
Define pH.
Define pH.
Derive the relation pH + pOH = 14.
Define pH.
Define pH.
Define pOH.
Derive the relation pH + pOH = 14.
Define the following term:
pOH
