Calculating Concentrations in a 1.0-L Buffer Solution with Added HCl

[Ki-nana18]

Homework Statement

A 1.0-L buffer solution is 0.105 M in HNO₂ and 0.180 M in NaNO₃. Determine the concentrations of HNO₂ and NaNO₃ after addition of 1.8 g HCl.

Homework Equations

None

The Attempt at a Solution

I turned 1.8 g of HCl into mols and got 0.0494 mol of HCl. I subtracted this number from .105 M to find the new concentration of HNO₂ and got 0.154 M. For NaNO₃ I added 0.0494 and got 0.229 M but these answers were wrong. So what is the process to solve this problem?

 

[Borek]

Technically speaking HNO₂/NO₃^- mixture is not a buffer.

 

[Ki-nana18]

It's supposed to be NaNO₂.

 

[Borek]

got 0.0494 mol of HCl. I subtracted this number from .105 M (...) and got 0.154 M.

Check your math and pay more attention to what you add/subtract. Idea is - in general - OK, but the execution is horrible.

 

[Ki-nana18]

I got the right answers, thank you for your help.