# chemestry

Please could anyone help me to give me solution of this problem:
Calculate the pH of a solution obtained by mixing 50 mL of NH3 0.1 M (Kb = 1.8•10–5 mol/L) and 25 mL of HCl 0.2 M

1. 👍
2. 👎
3. 👁
1. Note the correct spelling of chemistry.
NH3 + HCl ==> NH4Cl

mols NH3 = M x L = 0.1 x 0.05 = 0.005.
mols HCl 0.2 x 0.025 = 0.005.
You see this is an exact neutralizing solution; you have no HCl or NH3 left and have formed 0.005 mols NH3 in 75 mL solution so (NH4Cl) = 0.005/0.075 = approx 0.067 M NH4Cl. The pH of this solution is that due to the hydrolysis of the NH4^+.

....NH4^+ + H2O ==> H3O^+ + NH3
I...0.067............0.......0
C....-x..............x.......x
E...0.067-x..........x.......x

Ka for NH4^+ = (Kw/Kb for NH3) = (x)(x)/(0.067-x)
Solve for x = (OH^-) and convert to pH.

1. 👍
2. 👎

## Similar Questions

1. ### chemistry

5.85g of sodium chloride is dissolved in 250mL of solution. Calculate: a)the molarity of the solution b)the mass percentage of the solute. can we use the given volume(i.e,250mL as total volume of the solution or volume of water in

2. ### chemistry

Calculate the grams or milliliters of solute needed to prepare the following solutions. 1.)75. g of a 7.0 % (m/m) KCl solution 2.) 1250 mL of a 8.0 % (m/v) NH4Cl solution 3.) 270. mL of a 15.0 % (v/v) acetic acid solution I really

3. ### chemistry! URGENT

A standard solution is prepared for the analysis of fluoxymesterone (C20H29FO3), an anabolic steroid. A stock solution is first prepared by dissolving 10.0 mg of fluoxymestrone in enough water to give a total volume of 500.0 ml. A

4. ### Chemistry

A solution is prepared by mixing 1.00g ethanol (C2H5OH) with 100.0g water to give a final volume of 101.mL. Calculate the molarity, mass percent and mole fraction of ethanol in the solution.

1. ### chemistry HELP!

Solve an equilibrium problem (using an ICE table) to calculate the pH of each solution: a solution that is 0.170 M in HC2H3O2 and 0.105 M in KC2H3O2

2. ### chemistry

A. Strong Base 1.) What is the concentration of a solution of KOH for which the pH is 11.89? 2.) What is the pH of a 0.011M solution of Ca(OH)2? B. Weak Acid 1.) The pH of a 0.060M weak monoprotic acid HA is 3.44. Calculate the Ka

3. ### Chemistry

Determine how many mL of solution A (acetic acid-indicator solution) must be added to solution B (sodium acetate-indicator solution) to obtain a buffer solution that is equimolar in acetate and acetic acid. Solution A: 10.0 mL

4. ### GENERAL CHEMISTRY

CALCULATE THE pH AND HYDROLYSIS IN 0.10 M AlCl3 SOLUTION.Ka = 1.2 X 10-5 FOR [Al(OH2)6]+3,OFTEN ABBREVIATED Al+3.TELL WHETHER pH IS ACID OR BASE.GIVE IONIC EQUATION. Help us a little by telling us how much you know to do and

1. ### chemistry

When excess solid Mg(OH)2 is shaken with 1.00 L of 1.2 M NH4Cl solution, the resulting saturated solution has pH = 9.30. Calculate the Ksp of Mg(OH)2 I am not sure where to even begin on this problem.

2. ### Chemistry

An aqueous solution is 8.50% ammonium chloride, NH4Cl, by mass. The density of the solution is 1.024g/mL. Calculate the molality, mole fraction, and molarity of NH4Cl in the solution. I know the formulas needed but I'm not sure

3. ### Chemistry

A is a solution of trioxonitrate (v)acid, HNO3 of unknown concentration.B is standard solution of sodium hydroxide containing 4.00g per dm3 of solution. 25 cm3 portion solution B required an average of 24.00cm3 of solution A for

4. ### Equilibria

How to calculate the [Cu2^+] in a solution that was initially 1.0 M NH3 and 0.10 M Cu2^+ ? Kf value for Cu(NH3)4 ^ 2+ = 2.1*10^13 Please give me a detailed way of doing this problem. Thank you very much