Advertisements
Advertisements
Question
Calculate the pH of the following solutions:
0.3 g of Ca(OH)2 dissolved in water to give 500 mL of solution.
Advertisements
Solution
Strength of Ca(OH)2 = `0.3/500 xx 1000`
= 0.6 gL-1
Molar mass of Ca(OH)2 = 40 + 32 + 2 = 74
Molarity of Ca(OH)2 = `0.6/74` = 8.11 x 10-3M
1 mole of Ca(OH)2 = `0.6/74` = 8.11 x 10-3 M
1 mole of Ca(OH)2 on dissociation produces
two moles of OH-1 ions.
`therefore ["OH"^-] = 2xx8.11xx10^(-3)"M"`
= `16.22 x 10^(-3)"M"`
But `["H"^+]["OH"^-] = "k"_"w" = 1 xx 10^(-14)`
`therefore ["H"^+] = (1 xx 10^(-14))/["OH"^-] = (1 x 10^(-14))/(16.22 xx 10^(-3))`
= `6.16 xx 10^(-3)`M
Now pH = `- log["H"^+]`
= `- log[6.16 xx 10^(-13)]`
= `- [log 6.16 + log^(-13)]`
= `- [0.7896 - 13]`
`= 12.2104`
APPEARS IN
RELATED QUESTIONS
Assuming complete dissociation, calculate the pH of the following solution:
0.002 M KOH
Calculate the pH of the following solution:
1mL of 13.6 M HCl is diluted with water to give 1 litre of solution.
Calculate the pH of the resultant mixtures: 10 mL of 0.1M H2SO4 + 10 mL of 0.1M KOH
Answer the following in one sentence :
Calculate the pH of 0.01 M sulphuric acid.
Derive the relation pH + pOH = 14.
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.
Answer the following :
The pH of rainwater collected in a certain region of Maharashtra on a particular day was 5.1. Calculate the H+ ion concentration of the rainwater and its percent dissociation.
Calculate the pOH of 10-8 M of HCl.
Which of the following is INCORRECT statement?
Select the INCORRECT relation.
The aqueous solutions of sodium formate, anilinium chloride and potassium cyanide are respectively.
The percentage of pyridine (C5H5N) that forms pyridinium ion (C5H5NH) in a 0.10 M aqueous pyridine solution (Kb for C5H5N = 1.7 × 10−9) is ____________.
Equal volumes of three acid solutions of pH 1, 2 and 3 are mixed in a vessel. What will be the H+ ion concentration in the mixture?
If pKb for CN− at 25°C is 4.7, the pH of 0.5 M aqueous NaCN solution is ______.
Calculate the pH of the buffer solution containing 0.5 mol NaF and 0.015 mol HF per litre. [pKa = 3.1427].
Derive relationship between pH and pOH.
Define pH.
Derive relationship between pH and pOH.
Define pH.
