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Solutions

Question
CBSEENCH12011309

What is the [OH-] in the final solution prepared by mixing 20.0 mL of 0.50 M HCl with 30.0mL of 0.10 Ba(OH)2?

  • 0.10 M

  • 0.40 M

  • 0.0050 M

  • 0.12 M

Solution

A.

0.10 M

Number of milliequivalents of HCl = 2 x 0.050 x 1 = 1
Number  of milliequivalents of Ba(OH)2 = 2 x 30 x 0.10 = 6
[OH]- of final soluton 
milliequivalent of Ba(OH)2 
equals space fraction numerator negative milliequivlent space of space HCL over denominator total space volume end fraction
equals space fraction numerator 6 minus 1 over denominator 50 end fraction space equals space 0.1 space straight M