[MartynYarrow]

In the determination of a mixture of NaCl and NaBr, 2.000g of the mixture is dissolved in water and made up to 250ml in a graduated flask. 25.0ml of this halide solution mixture required 24.80ml of 0.100M AgNO3 solution to react. Calculate the composition in weight of the mixture.

my attempt:

NaCl + AgNO3 ----> NaNO3 + AgCl
NaBr + AgNO3 ----> NaNO3 + AgBr

no. of moles of AgNO3  = 0.100 x 24.80/1000= 0.00248
no. of moles of NaCl + NaBr in 25.0ml solution = 0.00248

then I failed to continue....

[Borek]

You have two sums - sum of masses and sum of number of moles. This gives two equations in two unknowns.

[MartynYarrow]

Let there're x grams of NaCl and y grams of NaBr

x + y = 2.000g -----------(1)

x/58.5 + y/102.9 = 0.0248 --------------(2)

By solving (1) and (2),

x= 0.727 and y= 1.273.

Is there any mistake in my calculation?

[Borek]

Your equation (2) lists 0.0248 instead of 0.00248. Could be it is just a typo. Otherwise equations are correct.