Share
Explore BrainMass

Acids and Bases

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

Basic Techniques in Cell Biology and Biochemistry

The only problems that need to be done are numbers (3) and (4) on the second scanned document and the question below . Numbers (1), (2), (5) are finished problems that do not need to be done so problems (3) and (4) should be done using the same format (do Calculations and preparation)as those. Also please answer this ques

pH of a mixture of .001M sodium bicarbonate dissolved in water

How do you go about calculating the pH of .001M sodium bicarbonate (NaCO3) dissolved in water.....I some how derived the right answer which is pH = 8.3 but really have no idea how /i actually got the answer. How would I go about deriving the amount of [H+] so that I could use the equation [H+] = -log(???) = pH = 8.3

pH and Molarity

Please help with the following problems. a.) Giving the reason for your answer, which would you expect to have the higher value of pH, a 1.0M solution of the strong acid, HCl or a 1.0M solution of the weak acid, acetic acid, CH3COOH? b.) Why is it that we can say that ozone in the stratosphere is beneficial to

Particulates, Concentration and Combining Substances

a) A water sample contains 0.0700 grams of arsenic in 10.0L of water. What is the concentration of the arsenic in parts per million (ppm)? b) If a person breathes in 22m3 of air per day and the air contains 0.205 milligrams of particulates per m3 how many grams of particulates does the person breathe in per day? c) Expl

Stoichiometry Problems, Limiting Reagent, Acid/Base, Balancing Chemical Equations

1. A solution is prepared by dissolving 10.8g ammonium sulfate in enough water to make 100.0mL of stock solution. A 10.00mL sample of this stock solution is added to 50.00mL of water. Calculate the concentration of ammonium ions and sulfate ions in the final solution. 2. One of the most commonly used white pigments in paint

Quantative Analysis of Acid in Vinegar

Acid content of vinegar Flask 1 Flask 2 Inital volume of NaOH in burette 0 17.5 Final volume of NaOH in burette 17.5 35.3 Volume of NaOH used for titration

Acid Base Reaction and Oxidation Numbers

1) Pennies made after 1982 contain 97% zinc by mass. A student wants to prove this by filing the copper outside the penny until he sees zinc and then putting the penny in a 1.00 M HCl solution. The zinc will be oxidized and the H+ (from the HCl) will be reduced: Zn + 2H+ ----- Zn2+ + H2 If the entire pen

Molecular, Complete Ionic, and Net Ionic Equations

Write the molecular, complete ionic, and net ionic equations for the reactions that occur, if any, when solutions of the following substances are mixed: a.) nitric acid and barium carbonate b.) zinc chloride and lead nitrate c.) acetic acid and sodium hydroxide d.) calcium nitrate and sodium carbonate e.) ammonium chlorid

What is the limiting reagent? Questions about chemical reactions

Please show how to solve the following questions: 2Al (s) + 2KOH (aq) + 4 H2SO4 (aq) + 22 H2O (l) --> 2KAl (SO4)2*12H2O (s) + 3H2 (g) 12.0 g of Al, 420 mL 2.0M KOH, 216 mL H2SO4 placed in 300 mL ice bath (water in excess) 1) What is the limiting reagent? 2) How much aluminum is necessary to produce 18g of alum? 3)

Reaction between aluminum hydroxide and sulfuric acid

Solid aluminum hydroxide Al(OH)3 (s) reacts with aqueous sulfuric acid H2SO4 (aq) to produce aluminum sulfate Al2(SO4)3 (aq) and water. We combine 30.0g of Al(OH)3 (s) and 75.0 ml of 2.00 M H2SO4 (aq), and the reaction goes to completion. Subsequent analysis reveals that 12.3 g of Al2(SO4)3 was formed. What is the percent yield

Citric Acid and Fertilizer

Problem 1: Citric acid is concentrated in citrus fruits and plays a central metabolic role in nearly every animal and plant cell. How many moles of citric acid are in 1.90 qts of lemon juice *d=1.09 g/ml* that is 6.62% citric acid by mass? Problem 2: Nitrogen *N*, phosphorus *P*and potassium *K* are the main nutrients

Gas Laws and Stochiometry

1. How many significant figures does the sum of the following contain? 8.520 + 2.7? 2. How many moles of oxygen atoms are there in 10 moles of KCIO3? 3. The oxidation number of N in NaNo3 is? 4. What element is oxidized in the following chemical reaction? 3Cu + 8HNO3 ----> Cu(NO3) + 2NO + 4H2O 5. At what temp. will

Volume of Sulfuric Acid

What volume of 16 M sulfuric acid must be used to prepare 1.5 L of a 0.1 M sulfuric acid? a. 9.4 mL solution b. 9.4 L solution c. 16 mL solution d. 16 L solution

Benzoic acid with hydroxide ion - extraction with sodium hydroxide

Show an equation for the reaction of benzoic acid with hydroxide ion? If you were performing an experiment with a Grignard reagent phenylmagnesium bromide with dry ice (carbon dioxide) in ether to create benzoic acid, why would it be necessary to extract the ether layer with sodium hydroxide?

Solving for the products of reactions

(See attached file for full problem description) --- 1. Fe²+ and Sb³- 2. Mg²+ and As³- 3. Al³+ and O²- 4. Co³+ and I- 5. Sr² + and P³- 6. Ca²+ and C4+ 7. Fe³+ and As³- 8. Na + and S² ˉ Write the name or formula for these compounds: 1. tin (II) acetate 2. bromous acid 3. copper(II) permanganate

Mechanisms for three reactions

Sn + 2I2 ---> SnI4 (Ac2O,AcOH,reflux on arrow) SnI4 + 2PPh3 ---->(PPh3)2SnI4 (CHCl3 on arrow) SnI4 + (Me2SO)2 ----> SnI4(Me2SO)2 (CH2Cl2 on arrow) Give mechanisms for these reactions if there is any.

Solubility Problems with Ksp

Q#1 (Common ion problem) What is the solubility,in mg/mL of BaF2 in a)Pure Water b)in a solution containing 5.0mg/mL of KF Ksp of BaF2=1.0*10^-6 Q#2 Effect of pH on solubility a)Calculate the solubility of a saturated solution og Mg(OH)2 on pure water.(My answer is 1.65096*10^-4M b)Calculate the solubility of the sa

Hess' Law of Additive Equations for Reactions

Using Hess' Law of additive equations, rearrange and/or multiply the following reactions in order to find the enthalpy for the radical reaction between hydrochloric acid and isopropyl alcohol (CH3CHOHCH3) to form water and isopropyl chloride. The dots you see indicate a radical, which is much different than an ion or an element

Solubility and Titration

(See attached file for full problem description) --- 1. Tooth enamel consists of hydroxyapatite, Ca5(PO4)3OH (Ksp = 6.8x10-37). Fluoride ion added to drinking water reacts with Ca5(PO4)3OH to form the more tooth decay-resistant fluorapatite, Ca5(PO4)3F (Ksp =1.0x10-60). Fluoridated water has dramatically decreased cavities