Share
Explore BrainMass

Acids and Bases

pH of Na2S and LiNO3 solutions

example 1: A solution is prepared by adding 0.1 Mol of sodium sulfide, Na2S, to 1.00 L of water. The solution is: - basic - neutral - acidic example 2: A solution is prepared by adding 0.1 Mol of lithium nitrate LiNO3, to 1.00 L of water. The solution is: - basic - neutral - acidic

pH of buffer solution

Hydrofluoric acid (HF) has an equilibrium constant Ka value of 7.2 x 10^- 4. Part a: 0.250 mol of F-- ions (in the form of NaF) are added to 1.0 Liters of 0.1 mol L-1 aqueous HF. Calculate the resulting pH? Part b: The solution produced in (part a) is added 10.0 ml of 5.0 mol L-1 NaOH. Calculate the resulting PH?

Disodium edetate

5. 0.1060g of sodium carbonate, dissolved in 20ml of water, was expected to give a titre of approximately 20ml of hydrochloric acid. what would you expect the approximate titre value to be if the carbonate had been dissolved in 40ml of water? 6. 20ml of a 1.103% w/v calcium lactate solution was analysed by titration against d

Moles and Formulas for Solutions

1. In a standarisation of hydrochloric acid solution, 0.1232g of sodium carbonate were used. calculate the number of moles of sodium carbonate used. 2. In a standarisation of hydrochloric acid solution, 0.1099g of sodium carbonate were used. This resulted in a titre value of 25.49ml. calculate the number of moles of hydrochlo

Determine the molar mass.

Acetylsalicylic acid acid is the active ingredient in aspirin. It took 35.17 mL of 0.5065 M sodium hydroxide to react completely with 3.210 g of acetysalicylic acid. Acetylsalicylic acid has only one acidic hydrogen. What is the molar mass of acetylsalicylic acid? I know the answer but I need help to set up the problem and to k

Carbonate chemistry --- Impact of solubility on ability to increase pH?

How does the solubility of a particular reactant affect its ability to raise pH? I am particularly interested in the difference between sodium carbonate and calcium carbonate. Calcium carbonate is much much less soluble than sodium carbonate. However, does the solubility of the carbonate matter when adjusting pH from say

Aluminum sulfate as a flocculant

In a lab experiment, a solution of weak acids in water exhibit a pH of 3.7; the solution is known to have a known quantity of dissolved solids in solution. Paper makers alum (aluminum sulfate = Al2(SO4)3) is supposed to be used to coagulate/flocculate the dissolved solids in order to precipitate those solids. In the course

Carbonate Chemistry

I have a lab experiment in which I have a slurry of wood pulp at a pH of 4.0; I'm asked to use sodium carbonate to raise the pH of the slurry to pH 5.5. I then press the wood slurry to de-water and place it in an oven until it is bone dry. I then take the wood sample out of the oven and place it in a bath of water to determine h

Separation of A Three Component Mixture by Extraction

2. Determine the amount of each component recovered and total their masses. Calculate the % recovery based on your starting mass. Amine with watch glass weighed 18.5197g - 18.4998g = 0.0199g, substance was yellow. Carbonoxylic acid with watch glass weighed 18.7402g - 18.7237g = 0.0165g. 3. Calculate the % composition of the mi

Multiple chemical reaction questions

1. The following is best described by which type of reaction? CaCO3 --> CaO + CO2 A. decompostion B. acid-base neutralization C. single displacement D. redox E. double-displacement (metathetical) 2. The following best describes which type of reation? 2Ca + O2 --> 2CaO a. decomposition b. acid-base neutraliz

Determine solubility of boric acid (H3BO3) at various pH's

This problem indicates that 1 gram of hydrated boric acid (H3BO3) is added to 1 liter of water at pH 7.0 and at standard temperature. The solubility is stated in the problem as 5.7 grams per 100 ml of solution. A pKa is also given as 9.24. 1) What does the pKa value mean? 2) How would I determine the amount of boric acid

Solubility of reaction

The Ksp for Fe(OH)2 is 1.8 x 10-11. Will a precipitate form if an 0.4M solution of FeCl2, has its pH raised to 8.3? What is the solubility of Mg+2 in 0.03M HF? Ka for hydrofluoric acid is 6.6 x 10-4. The Ksp for magnesium fluoride is 3.7 x 10-8 Also: Complete the following reactions: a. H2PO4^- +H^+ ->

Vitamin C Content of Juices

Assignment 1 of Procedure 1 1. Calculate the molarity of the freshly-prepared ascorbic acid standard (known strength) solution: (a) Mass of ascorbic acid used:0.05g (b) Moles of ascorbic acid (MW=176.1 g/mol):not sure 0.000284 (c) Total volume of standard solution prepared (mL):100.01mL (d) Asc

Equilibrium Acid-Base Reactions

40.00 mL of an unknown ammonia solution is titrated with 25.0 mL of 0.105M HCl to the equivalence point. The Kb for ammonia is 1.8 x 10-5. What was the concentration of the original ammonia solution? What is the concentration of NH4Cl at the equivalence point? What is the pH at that point?

Calculate the pH for a buffer solution.

Calculate the pH for a buffer solution prepared by mixing 100. mL of 0.60 M NH3 and 200. mL of 0.45 M NH4Cl. The Ka of NH4 + = 5.6 x 10^-10. a) 8.65 b) 9.08 c) 9.87 d) 4.90 e) 6.62

Glucose Synthesis Problems

Glucose is soluble in benzene. If alpha-D-glucose is dissolved in benzene, essentially no alpha-D-glucose is formed. However, if small amounts of phenol and pyridine are added, then the equillibrium amount of alpha-D-glucose is formed but slowly. If, to a solution of alpha-D-glucose in benzene, a small amount of 2-hydroxy-py

Conversion formula between pressure units

What is the formula for converting atm to Torr? example: 1.87 atm to Torr Also what is the formula for converting Torr to mmhg? example: 748 Torr to mmHg What about mb to kPa? example: 998mb to pKa Then in. Hg to atm example:26,88 in Hg to atm

Acid-Base Equilibria

1. Write formulas for the conjugate bases for each of these acids: a) HCl b) CH4 c) HSO3- d) H2SO4 e) NH3 2. In the following reactions, identify the Lewis acid and the Lewis base: a) Fe3+ + 6H2O ←→ Fe(H2O)36+ b) BF3 + NH3 ←→ F3BNH3 c) BF3 + F- ←→ BF4-

Chemistry Element Questions

1. What is the volume of 1.20 x 1022 molecules of nitric oxide gas, NO, at STP? 2. What is the mass of sodium phosphate (163.94 g/mol) that yields 1.00 g of calcium phosphate (310.18 g/mol) precipitate? __CaCl2(s) + __Na3PO4(aq) → __Ca3(PO4)2(s) + __NaCl(aq) 3. How many moles of calcium metal react to yield 0.50

Calcium carbonate in limestone

The white limestone cliffs of Dover, England, contain a large percentage of calcium carbonate (CaCO3). A sample of limestone with a mass of 84.4 g reacts with an excess of hydrochloric acid to form calcium chloride. CaCO3 + 2HCl ----> CaCO3 + CaCl2 + H2O + CO2 The mass of calcium chloride formed is 81.8 g. What is the percen

the density (in g/L) of the CO2

A 1004.0-g sample of CaCO3 that is 95.0% pure gives 225 L CO2 at STP when reacted with an excess of hydrochloric acid. CaCO3 + 2HCl -- > CaCl2 + CO2 + H2O What is the density (in g/L) of the CO2?

Acid-Base Calculations

1.) Calculate the four values of pH, pOH, [H+], and [OH-] for a 0.100 M of HCl. 2.) Calculate the four values of pH, pOH, [H+], and [OH-] for a 0.00250 M NaOH solution. 3.) Calculate the four values of pH, pOH, [H+], and [OH-] fo a 0.00150 solution of nitric acid (HNO3). 4.) The Ka of HCl is known to be about 10^7. What is th

Mole, Mass, Enthalpy, and Energy Change Problems

See attached file for full problem description. 1. Which is not a solution? brass, fog, hydrochloric acid, or wine 2. How Many Moles of CuO can be produced from 0.0450 mol if Cu2O in the following reaction? 2 Cu2O(s) + O2(g) -> 4 CuO(s). 3. Methane and Oxygen react to form carbon dioxide and water. What mass of wa

pH Adjustment of a Solution with NaOH or Ca(OH)2

Assume you have a 64000L volume of solution (predominantly water) with a pH of 4.03. 1. How much NaOH would be required to raise the pH to 5.5? 2. Or, if using Ca(OH)2 --- how much calcium hydroxide would be required to raise the pH of this solution to 5.5? In each case, assume full ionization of the base.

Calculating mass of sulfuric acid to affect pH change?

I have a 2 part question concerning the use of H2SO4 to adjust the pH of a solution: 1. How many grams per liter of H2SO4 is required to adjust the pH of a solution from 3.8 to 2.8 assuming the sulfuric acid fully ionizes? 2. If in reality however, the actual sulfuric acid ionization/dissociation is a 2 step process and no

Forming Aluminum Hydroxide from Aluminum Sulfate and Water

Assume we have a 1000L tank of water and very dilute weak acids. To this tank we add and dissolve 260 grams AL2(SO4)3 (solid granules) --- the resultant pH is 4. The intention is to form AL(OH)3 solids/particles in this reaction. Question 1: How much Al(OH)3 will be formed in this reaction at pH=4.0 Question 2: If the pH w

Acid Base Titration

A 0.394 sample of potassium hydrogen phthaate (KHC8H4O4) is dissolved in 100-Ml of water. 13.9-ml of sodium hydroxide solution are required to reach the equivalence point, what is the normality,N, of sodium hydroxide? KHC8H4O4's equivalent weight is 204.2g/equiv and a 0.294g sample of an unknown acid requires 13.4-ml of 0.132N N