pH of buffer after adding NaOH to HONH2/HONH3Cl mixture

[disneychannel]

I have no idea how to find the pH of a buffer solution:
Please step by step!
Calculate the pH after 0.020 mol NaOH is added to 1.00 L of:
a mixture containing 0.100 M HONH₂ and 0.100 M HONH₃Cl

please step by step instruction so I can follow and do other problems on my own! Thanks

 

[dacruick]

its been a while but don't you just find the moles of each. then find out how many OH or H you have and find the ph like that? or was that not buffer?

 

[disneychannel]

i don't believe that's how you do it

 

[Borek]

One of the substances listed reacts with NaOH. Assume reaction is quantitative, then it is just Henderson-Hasselbalch equation.

 

[disneychannel]

would the answer be 6.18?

 

[dacruick]

ahhh the henderson hasslebach i remember that one. Yeah you just have to use that equation with the mols of acid and base taht you have.

 

[Borek]

Depends on what value you have used for pKa. Correct ball park for sure.