please show work Calculate the theoretical pH of 10 mM NaOH using the data below

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Calculate the theoretical pH of 10 mM NaOH using the data below: NaOH is a strong base, dissociates completely, thus [OH] is equal to [NaOH] ion product water [H^+][OH^-] = 1.0 times 10^-14 M^2 pH = -log [H^+] HCl is a liquid with molecular weight of 36.5 g/mol. Usually HCl is sold as a solution, and figuring out how to prepare necessary dilutions could be tricky. We will try to do it step by step. a. Calculate the theoretical dry mass in g HCl to make 100 ml of 10 mM solution of HCl. b. Since HCl is not a solid, but rather a liquid, we need to measure the amount of stock HCl in ml, not in grams. If the density of HCl solution is 1.27 g/ml, how many ml of liquid 100% HCl (instead of grams you easily calculated in the previous step) do you need to take to prepare 100 ml of 10 mM solution of HCl? c. You have 37% HCl solution (density is always 1.27 g/ml). Calculate the amount of this solution you need to take to prepare 100 ml of 10 mM of HCl. d. Calculate the theoretical pH of this solution (HCl is a strong acid and dissociates completely).

Explanation / Answer

1.pH= -log [H+] and pOH =-log[OH-]

given 10mM NaOH which ionizes completely hence [OH-]= 10mM= 10*10-3 M, pOH= -log(0.01)= 2

pH= 14-pOH= 14-2= 12

2. Moles of HCl in 10mM of 100ml HCl = molarity* Volume (L)= 10*10-3*100/1000 =0.001

Mass= moles* Molar mass of HCl= 0.001*36.5 gm =0.0365 gm

Volume of solution =1.27 g/cc

Volume of HCl =0.0365/1.27 =0.02874cc

3. Mass of solution = volume*density =100*1.27= 127 gm

mass of HCl = 37%, mass of HCl = 127*0.37= 46.99 gm

mass of HCl required in 100ml 0f 10mM= 0.0365 gm

46.99 gm of HCl is there in 127 gm

0.0365 gm of HCl will be there in 127*0.0365/46.99=0.098 gm of solution.

pH= -log [H+]= -log (10/1000)= 2

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