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Chemical Kinetics

Question
CBSEENCH12010784

Solid Ba (NO3)2 is gradually dissolved in a 1.0x 10−4 × Na2CO3 solution. At what concentration of Ba2+ will a precipitate begin to form?(Ksp for BaCO3 = 5.1 ×10−9  )

  • 4.1 x 10-5 M

  • 5.1 x 10-5 M

  • 8.1 x 10-8 M

  • 8.1 x 10-7 M

Solution

B.

5.1 x 10-5 M

Na subscript 2 CO subscript 3 space rightwards arrow with space on top space 2 Na to the power of plus space plus space CO subscript 3 superscript 2 minus end superscript space
space space space space space space space space space space space space space space space space space space space space space space space space space space 1 space straight x space 10 to the power of negative 4 end exponent space straight M
BaCO subscript 3 space space space space space space space space space space space space space Ba to the power of 2 plus end exponent space plus space CO subscript 3 superscript 2 minus end superscript
Ksp space equals space left square bracket Ba to the power of 2 plus end exponent right square bracket left square bracket CO subscript 3 superscript 2 minus end superscript right square bracket
5.1 space straight x space 10 to the power of negative 9 end exponent space equals space left square bracket Ba to the power of 2 plus end exponent right square bracket left square bracket 1 space straight x space 10 to the power of negative 4 end exponent right square bracket
left square bracket Ba to the power of 2 plus end exponent right square bracket space equals space fraction numerator 5.1 space straight x space 10 to the power of negative 9 end exponent over denominator 1 space straight x space 10 to the power of negative 4 end exponent end fraction
space equals space 5.1 space straight x space 10 to the power of negative 5 end exponent space straight M