Question

Calculate the pH of the resultant mixtures:
10mL of 0.2M Ca(OH), + 25 ml. of. IM HC​

Answer 1

Answer:

Total number of moles present in 10 mL of 0.2 M calcium hydroxide are 1000

10×0.2=0.002 moles.

Total number of moles present in 25 mL of 0.1 M HCl are 1000 ,25×2 =0.0025 moles.

Ca(OH) 2 +2HCl→CaCl 2+2H2O

1 mole of calcium hydroxide reacts with 2 moels of HCl.

0.0025 moles of HCl will react with 0.00125 moles of calium hydroxide.

Total number of moles of calcium hydroxide unreacted are 0.002−0.00125=0.00075 moles.

Total volume of the solution is 10+25=35 mL.

The molarity of the solution is 35

0.00075×1000=0.0214M

[OH − ]=2×0.0214=0.0428M

pOH=−log0.0428=1.368

pH=14−pOH=14−1.368=12.635