[chilli]

i have tried to deal with this simple question for a while and somehow still managing to get confused:
HCl solution volume = 100ml
concentration = 0.1M
adding to it:
1. 100ml NaOH solution, c = 0.1
2. 100ml HNO₃ solution , c= 0.1
3. 100ml HCN solution c = 0.1
4. 100ml purified water
How will adding these solutions will affect the original solution's pH?
In what range the pH will be at the end of the experiment <7 >7 or = 7 
I am not sure how to approach this question will appreciate any help

[billnotgatez]

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[chilli]

Thank u for your reply I have read the rules but finding it hard to explain how I tried to solve it, very new to chemistry studies and I feel like I am missing something obvious
Naoh is a strong base will it neutralize all the H⁺ in the original solution and the new solution will become neutral?
2 and 3 are acids and are added with same v and c so will the pH remain the same?
Is there any way to calculate it to determine in what range the pH will be?

[billnotgatez]

Do you have to know the specific pH or just 1 of 3 general possibilities?

In what range the pH will be at the end of the experiment <7 >7 or = 7

If you add an acid solution to and acid solution do you get an acid solution or a base solution or a neutral solution?

There are ways you can calculate the likely final specific pH and 
http://www.chembuddy.com/
is a place to look
But is it really necessary for this given question?

As a side note -- sometimes it takes a while for help to arrive - especially during holidays.

[chilli]

Hi, tyvm for your help
just the general possibilities, and how will adding the solutions will change its original pH.
To your question I think I will get an even more acidic solution but because they are in a solution (+water I guess) its confusing me.
my answers are:
1. pH will go down
2. pH will not change
3. pH will not change
4. pH will grow
but regarding to where in range they will be im a bit lost regarding 1 and 4 because I guess in 2,3 it will stay below 7
again, tyvm I really appreciate it

[chilli]

sorry
1. pH will grow

[chilli]

managed   

[Borek]

Actually in 3^rd pH will change as well - HCN is a very weak acid, adding its solution you will be just diluting the HCl.

To be nitpickingly precise HNO₃ is a weaker acid than HCl so the pH will change as well in the 2^nd case, but the change is negligible.

[chilli]

Ty, I will mention it, just found out that in HCN there are 7 H₃O⁺ to 100,000 acid molecules where in HCl there are 100,000 H₃O⁺ for the same amount