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relaxin 11 months ago

Just remember that N1xV1 = N2xV2, where N can be percentage, molarity or normality; V is the volume.

Assuming X ml of the 82% is needed to mix with (140-X) ml of the 65%,

X.82 + (140-X).65 = 140 .76

Solve for X

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gene26 11 months ago

I did try to apply N1V1=N2V2
N1 = X.82 + (140-X).65
N2= .76
V1= ?

but I couldn't come up with a equation for N1this seems like a GRE math

when do we use N1/V1 = N2/V2

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relaxin 11 months ago

Your N1 is wrong (N is for concentration only). Since there are two solutions with different percentage involved, the total sum of N1V1 of the two solutions will be equal to N2V2 of the final solution.

V1 has different values for each of the original solutions, the sum should be equal to V2.