General Chemistry Answers

1. An experiment requires a solution that is 80% methyl alcohol by mass. What mass of methyl alcohol should be added to 20 g of water to make this solution?

2. Calculate the mole fraction of NaCl in a solution containing 12.6 g NaCl and 21.3 g KCl in 122 g of water.

3.A solution of phosphoric acid was made by dissolving 10.0 g of H3PO4 in 100.0 mL of water. The resulting volume was 104 mL. Calculate the molarity of the solution. Assume water has a density of 1.00 g/cm3.

What is the pH at the equivalence point for the titration of 0.23 M solutions of the following acids and bases.
1)NaHSO3 (for H2SO3: Ka1=1.5×10−2, Ka2=6.3×10−8) and NaOH
2)Ba(OH)2 and HBr

At 25 ∘C phosphoric acid, H3PO4, has the following equilibrium constants:
H3PO4(aq)+H2O(l)H2PO4−(aq)+H2O(l)HPO42−(aq)+H2O(l)⇌⇌⇌H3O+(aq)+H2PO−4(aq)H3O+(aq)+HPO42−(aq)H3O+(aq)+PO43−(aq) Ka1Ka2Ka3===7.5×10−36.2×10−84.2×10−13

What is the pH of a solution of 0.900 M KH2PO4, potassium dihydrogen phosphate?

1) A 68.0 mL volume of 0.25 M HBr is titrated with 0.50 M KOH. Calculate the pH after addition of 34.0 mL of KOH at 25 ∘C.

2) Consider the titration of 50.0 mL of 0.20 M NH3 (Kb=1.8×10−5) with 0.20 M HNO3. Calculate the pH after addition of 50.0 mL of the titrant at 25 ∘C.

3)A 30.0-mL volume of 0.50 M CH3COOH (Ka=1.8×10−5) was titrated with 0.50 M NaOH. Calculate the pH after addition of 30.0 mL of NaOH at 25 ∘C.

A certain weak acid, HA, with a Ka value of 5.61×10−6, is titrated with NaOH.More strong base is added until the equivalence point is reached. What is the pH of this solution at the equivalence point if the total volume is 30.0 mL ?

Suppose you are performing an experiment that requires a constant pH of 7.00.Calculate the ratio of conjugate base to weak acid required to prepare a buffer with pH= 7.00.

what is the percentage change in [H+] if pH of the blood changes from pH 7.4 to 7.2

Hi, I was going through your Answer on Question #56945 - Chemistry - General Chemistry. Question - The concentrations after mixing would become: NH3 - 2M; AgNO3 - 0.25M. How come you have used the initial values before mixing?

Raj