Advertisements
Advertisements
प्रश्न
Calculate the pH of the following solutions:
0.3 g of Ca(OH)2 dissolved in water to give 500 mL of solution.
Advertisements
उत्तर
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`
संबंधित प्रश्न
The concentration of hydrogen ion in a sample of soft drink is 3.8 × 10–3 M. what is its pH?
The pH of a sample of vinegar is 3.76. Calculate the concentration of hydrogen ion in it.
Assuming complete dissociation, calculate the pH of the following solution:
0.005 M NaOH
Assuming complete dissociation, calculate the pH of the following solution:
0.002 M KOH
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.
Derive the equation pH + pOH = 14.
Which of the following is CORRECT for an aqueous solution of NH4CN?
[Ka of HCN = 4.0 × 10−10, Kb for NH4OH = 1.8 × 10−5]
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 ____________.
The pH of an aqueous solution is Zero. The solution is ____________.
A lab assistant prepared a solution by adding a calculated quantity of HCl gas at 25°C to get a solution with [H3O+]= 4 × 10−5 M. Is the solution neutral (or) acidic (or) basic.
Calculate the pH of 0.04 M HNO3 solution.
The Ka value for HCN is 10−9. What is the pH of 0.4 M HCN solution?
Derive the relationship between pH and pOH.
The mole fraction of the solute molal aqueous solution is:
Define pOH.
Define pH.
Define pOH.
Derive the relation pH + pOH = 14.
Define the following term:
pH
