You mix 250 ml of 2.1 m hbr with 200 ml of 2.5 m koh. what is the ph of the resulting solution?

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1

you mix 250 ml of 2.1 m hbr with 200 ml of 2.5 m koh. what is the ph of the resulting solution?

@aibot

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To determine the pH of the resulting solution, we need to consider the reaction that occurs between hydrobromic acid (HBr) and potassium hydroxide (KOH). HBr is a strong acid and KOH is a strong base. When they react, they undergo a neutralization reaction to form water (H2O) and a salt, potassium bromide (KBr).

The balanced chemical equation for the reaction is as follows:
HBr + KOH → H2O + KBr

To find the pH of the resulting solution, we need to calculate the concentration of the resulting salt in the solution. Since both HBr and KOH react in a 1:1 ratio, we can determine the amount of moles of KBr formed using the equation:

moles of KBr = moles of HBr = moles of KOH

First, let’s calculate the moles of HBr:
moles of HBr = (volume of HBr solution in liters) x (molarity of HBr)
= (250 ml / 1000) x (2.1 mol/L)
= 0.525 mol

Next, let’s calculate the moles of KOH:
moles of KOH = (volume of KOH solution in liters) x (molarity of KOH)
= (200 ml / 1000) x (2.5 mol/L)
= 0.5 mol

Since the moles of KBr formed are equal to the moles of HBr and KOH reacted, we can say that the moles of KBr are 0.525 mol.

Now, let’s calculate the concentration of KBr in the resulting solution:
concentration of KBr = (moles of KBr) / (total volume of resulting solution in liters)
= 0.525 mol / (250 ml + 200 ml) / 1000
= 0.525 mol / 0.45 L
= 1.167 mol/L

To find the pH of the resulting solution, we need to calculate the concentration of the hydrogen ions (H+). Since KBr does not significantly dissociate in water, we can ignore its contribution to the H+ ions.

In this case, we have a solution of a salt (KBr) with a concentration of 1.167 mol/L. Since KBr is the salt of a strong acid (HBr), it does not affect the pH of the solution. Therefore, the resulting solution will have a neutral pH of 7.

So, the pH of the resulting solution after mixing 250 ml of 2.1 M HBr with 200 ml of 2.5 M KOH is 7.

I hope this answers your question. Let me know if you need any further clarification.

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