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This is where you must put your chemist's (or pharmacist's) hat on and look at your answer to see if it makes sense.

__very__ dilute hydrochloric acid.

The pH must be less than 7 so how can 8 be correct?

Yes I know this is what you will get if you just dilute the solution 1000 times and bung 0.00000001 into your calculator and take the negative of the log.

But this is a__very dilute__ solution , comparable with the concentration of hydrogen ions in pure water.

Have your studies covered how to handle this situation?

The actual pH works out at 6.98

Some online pH calculators will give you pH = 5 for number (4).

Actually it works out to 4.73 since sulphuric acid is diprotic, but Ka for the second proton is low.

for (1) you are asked for the pH ofand 2 are correct?I think number 1

The pH must be less than 7 so how can 8 be correct?

Yes I know this is what you will get if you just dilute the solution 1000 times and bung 0.00000001 into your calculator and take the negative of the log.

But this is a

Have your studies covered how to handle this situation?

The actual pH works out at 6.98

Some online pH calculators will give you pH = 5 for number (4).

Actually it works out to 4.73 since sulphuric acid is diprotic, but Ka for the second proton is low.

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I study HH equation. So, i am supposed to be able to find pH of them.This is where you must put your chemist's (or pharmacist's) hat on and look at your answer to see if it makes sense.

for (1) you are asked for the pH ofdilute hydrochloric acid.very

The pH must be less than 7 so how can 8 be correct?

Yes I know this is what you will get if you just dilute the solution 1000 times and bung 0.00000001 into your calculator and take the negative of the log.

But this is asolution , comparable with the concentration of hydrogen ions in pure water.very dilute

Have your studies covered how to handle this situation?

The actual pH works out at 6.98

Some online pH calculators will give you pH = 5 for number (4).

Actually it works out to 4.73 since sulphuric acid is diprotic, but Ka for the second proton is low.

In (1) There are $10^{-7} mol $ of HCl ?

NoIn (1) There are 10−7mol of HCl ?

You do not need the HH equation.I study HH equation. So, i am supposed to be able to find pH of them.

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How do you count for mol of HCl on (1) ?No

You do not need the HH equation.

What is 0.00000001 ?Yes I know this is what you will get if you just dilute the solution 1000 times and bung 0.00000001 into your calculator and take the negative of the log.

10^-7 is moles of HClCheck question (1) carefully.

What is 0.00000001 ?

[HCl]=10^-8

Concentration [HCl] = Concentration [H+] = [Cl-] = 1 x 10^−8M

But in pure water

[H+] = [OH-] = 1 x 10^−7M

So what is the total concentration of [H+] in the solution ?

What therefore is the pH of the solution?

Remember I said this is a

For less dilute (more concentrated) solutions we can ignore the effect of the water solvent.

So, pH is 7 from water

Concentration [HCl] = Concentration [H+] = [Cl-] = 1 x 10^−8M

But in pure water

[H+] = [OH-] = 1 x 10^−7M

So what is the total concentration of [H+] in the solution ?

What therefore is the pH of the solution?

Remember I said this is asolutionvery dilute

For less dilute (more concentrated) solutions we can ignore the effect of the water solvent.

NoSo, pH is 7 from water

Total [H+] in the solution = {(1 x 10^−7) + (1 x 10^−8 )}MSo what is theconcentration of [H+] in the solution ?total

What therefore is the pH of the solution?

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