Chemistry, 29.07.2019 21:20 caleelwittmann31

Starting with 250 ml of a 0.250 m solution of hbr; a) calculate the initial ph of the solution. b) calculate the ph after adding 250 ml of 0.125m naohc) calculate the ph after adding 500 ml of 0.125m naohd) calculate the ph after adding 600 ml of 0.125m naoh.

Answers: 3

Show answers

Answers

Answer from: alyssawage

pH = 0.602

pH = 1.5

pH = 7

pH = 12.1

Explanation:

a ) To calculate the pH, use the following equation:

pH = -log [H+]

Hbr is a strong acid, so the [H+] concentration can be calculated as follow:

[HBr] = 0.250 M

As acid Hbr:

Hbr = H+ + Br-

As strong acid HBr dissociates at all, so

[HBr] = [H+] = 0.250 M

So the pH:

pH = -log [0.250 M] = 0.602

b) Calculate the pH after adding 250 mL of 0.125M NaOH

In this point, the reactions starts:

HBr + NaOH = H2O + NaBr

- First, we gonna find the mol of each reactant:

HBr:

mol = [M] × L

mol = 0.250 M × 0.250 L

mol = 0.0625 mol HBr

NaOH:

mol = [M] × L

mol = 0.125 M × 0.250L

mol = 0.03125 mol NaOH

In base on the reaction, it’s needed 1 mol of NaOH to neutralize 1 mole of HBr, so to neutralize 0.0625 moles of HBr its needed 0.0625 mol of NaOH:

0.0625 mol HBr – 0.03125 mol HBr = 0.03125 mol HBr

These are the moles free in the solution, and we going to use them to calculate the pH:

pH = -log [ H]

pH = - log [ 0.03125 ] = 1.5

c) Calculate the pH after adding 500 mL of 0.125M NaOH

NaOH:

mol = [M] × L

mol = 0.125 M × 0.500L

mol = 0.0625 mol NaOH

In base on the reaction, it’s needed 1 mol of NaOH to neutralize 1 mole of HBr, so to neutralize 0.0625 moles of HBr its needed 0.0625 mol of NaOH:

0.0625 mol HBr – 0.0625 mol HBr = 0 HBr

pH = 7

d) Calculate the pH after adding 600 mL of 0.125M NaOH.

NaOH:

mol = [M] × L

mol = 0.125 M × 0.600L

mol = 0.075 mol NaOH

In base on the reaction, it’s needed 1 mol of NaOH to neutralize 1 mole of HBr, so to neutralize 0.0625 moles of HBr its needed 0.0625 mol of NaOH:

0.075 mol NaOH – 0.0625 mol NaOH = 00125 NaOH

These are the moles free in the solution, and we going to use them to calculate the pH:

pOH = -log [ OH]

pOH = - log [ 0.0125 ] = 1.90

pH + pOH = 14

pH = 14- pOH = 14 – 1.90 = 12.1

Answer from: Quest

Ithink its solid. hope this

Answer from: Quest

Carbon based or cells?

Another question on Chemistry

Chemistry, 21.06.2019 18:30

Which orbitals form a pi bond? a.the s orbital and three p orbitals b.the s orbital and two p orbitals c.overlapping p orbitals d.overlapping hybrid orbitals

Answers: 2

Answer

Chemistry, 22.06.2019 03:30

Adrop of acetone (nail polish remover) has a mass of 35 mg and a density of 0.788 g/cm3. what is its volume in cubic centimeters?

Answers: 3

Answer

Chemistry, 23.06.2019 08:10

Time remaining 58: 10 an atom that has 84 protons and 86 neutrons undergoes a reaction. at the end of the reaction, it has 82 protons and 84 neutrons. what happened to the atom? it accepted radiation in a chemical reaction it donated neutrons to another atom in a chemical reaction it emitted an alpha particle in a nuclear reaction. it accepted protons in a nuclear reaction. mark this and retum save and exit next submit

Answers: 3

Answer

Chemistry, 23.06.2019 09:10

In a 28 g serving of cheese curls there are 247mg of sodium. how much sodium is in a 12.5 ounce bag

Answers: 1

Answer

You know the right answer?

Starting with 250 ml of a 0.250 m solution of hbr; a) calculate the initial ph of the solution. b)...

Questions