New Semester
Started
Get
50% OFF
Study Help!
--h --m --s
Claim Now
Question Answers
Textbooks
Find textbooks, questions and answers
Oops, something went wrong!
Change your search query and then try again
S
Books
FREE
Study Help
Expert Questions
Accounting
General Management
Mathematics
Finance
Organizational Behaviour
Law
Physics
Operating System
Management Leadership
Sociology
Programming
Marketing
Database
Computer Network
Economics
Textbooks Solutions
Accounting
Managerial Accounting
Management Leadership
Cost Accounting
Statistics
Business Law
Corporate Finance
Finance
Economics
Auditing
Tutors
Online Tutors
Find a Tutor
Hire a Tutor
Become a Tutor
AI Tutor
AI Study Planner
NEW
Sell Books
Search
Search
Sign In
Register
study help
engineering
elementary principles chemical
Quantitative Chemical Analysis 8th edition Daniel C. Harris - Solutions
Make a list of the common strong acids and strong bases. Memorize this list.
The equilibrium constant for the reaction H2O ⇌ H+ + OH- is 1.0 × 10-14 at 25°. What is the value of K for the reaction 4H2O ⇌ 4H+ + 4OH-?
Write the autoprotolysis reaction of H2SO4.
Identify the Brønsted-Lowry acids among the reactants in the following reactions:a.b. KCN + HI = HCN + KI
Gaseous SO2 is created by combustion of sulfur-containing fuels, especially coal. Explain how O2 in the atmosphere makes acidic rain.
Identify the Lewis acids in the following reactions:a.b. BF3 + NH3 FB-NH3
Solubility products predict that cation A3+ can be 99.999% separated from cation B2+ by precipitation with anion X-. When the separation is tried, we find 0.2% contamination of AX3(s) with B2+. Explain what might be happening.
Find the concentration of Cu+ in equilibrium with CuBr(s) and 0.10 M Br-.
For the reactionat 298.15 K. Find the value of K for the reaction. HCO, = H* + CO , AG° = +59.0 kJ/mol %3D
(a) A favorable entropy change occurs when ΔS is positive. Does the order of the system increase or decrease when ΔS is positive?(b) A favorable enthalpy change occurs when ΔH is negative. Does the system absorb heat or give off heat when ΔH is negative?(c) Write the relation between ΔG, ΔH,
Write the expression for the equilibrium constant for each of the following reactions. Write the pressure of a gaseous molecule, X, as PX.a.b. 3Ag*(aq) + PO (aq) = Ag3PO4(s)
Why do we say that the equilibrium constant for the reaction H2O ⇌ H+ + OH- (or any other reaction) is dimensionless?
(a) From Kw in Table 6-1, calculate the pH of pure water at 0°, 20°, and 40°C.(b) For the reaction D2O ⇌ D+ + OD-, K = [D+][OD-] =1.35 × 10-15 at 25°C. In this equation, D stands for deuterium, which is the isotope 2H. What is the pD (= –log[D+]) for neutral D2O?Table 6-1 Temperature (°C)
Histidine is a triprotic amino acid:What is the value of the equilibrium constant for the reaction CO,H -NH CO, -NH HC-CH, K, = 3 x 102 HC-CH, NH, NH, к, 3 8.5 х 10-7 CO, -NH CO NH HC-CH2 К, 3 4.6 х 10 10 HC-CH, N. NH2 NH3
Succinic acid dissociates in two steps: K1 НОССH,СH,CОН НОССН,СН,СО + H* %3| || OCCH,CH,CO¯ + H* К, 3 2.3 х 10-6 HOCCH,CH,CO Calculate Kp1 and Kp2 for the following reactions: || OCCH,CH,CO¯ + H,0 = HOCCH,CH,CO + OH Кы Kp2 HOCCH,CH,CO¯ + H,0 2 HOCCH,CH,COH + OH
If each compound is dissolved in water, will the solution be acidic, basic, or neutral? (a) Na Br (e) (CH3),N CI (b) Na CH,CO, (f) (CH,),N*O-co, (c) NH CI (g) Fe(NO3)3 (d) K3PO4
For a solution of Ni2+ and ethylenediamine, the following equilibrium constants apply at 20°C:Calculate the concentration of free Ni2+ in a solution prepared by mixing 0.100 mol of en plus 1.00 mL of 0.010 0 M Ni2+ and diluting to 1.00 L with dilute base (which keeps all the en in its unprotonated
Is it possible to precipitate 99.0% of 0.010 M Ce3+ by adding oxalate (C2O42-) without precipitating 0.010 M Ca2+? CaC204 Ksp = 1.3 x 10-8 %3D Ce,(C,O4)3 Ksp 5.9 X 10-30
Is it possible to precipitate 99.0% of 0.010 M Ce3+ by adding oxalate (C2O42-) without precipitating 0.010 M Ca2+?
Fe(III) precipitates from acidic solution by addition of OH- to form Fe(OH)3(s). At what concentration of OH- will [Fe(III)] be reduced to 1.0 × 10-10 M? If Fe(II) is used instead, what concentration of OH- will reduce [Fe(II)] to 1.0 × 10-10 M?
Which will be more soluble (moles of metal dissolved per liter of solution), Ba(IO3)2 (Ksp = 1.5 × 10-9) or Ca(IO3)2 (Ksp = 7.1 × 10-7)? Give an example of a chemical reaction that might occur that would reverse the predicted solubilities.
Find [La3+] in the solution when excess solid lanthanum iodate, La(IO3) 3, is stirred with 0.050 M LiIO3 until the system reaches equilibrium. Assume that IO-3 from La(IO3) 3 is negligible compared with IO-3 from LiIO3.
Reaction 6-7 is allowed to come to equilibrium in a solution initially containing 0.0100 M BrO-3, 0.0100 M Cr3+, and 1.00 M H+.To find the concentrations at equilibrium, we can construct a table showing initial and final concentrations (see below). We use the stoichiometry coefficients of the
Consider the following equilibria in aqueous solution:(a) Calculate the numerical value of the equilibrium constant for the reaction(b) Calculate the concentration of AgCl(aq) in equilibrium with excess undissolved solid AgCl.c) Find the numerical value of K for the reaction (1) Ag* + Cl = AgCl(aq)
The U.S. Department of Agriculture provided homogenized baby food samples to three labs for analysis.3 Results agreed well for protein, fat, zinc, riboflavin, and palmitic acid. Results for iron were questionable: Lab A, 1.59 ± 0.14 (13); Lab B, 1.65 ± 0.56 (8); Lab C, 2.68 ± 0.78 (3) mg/100 g.
The U.S. Department of Agriculture provided homogenized baby food samples to three labs for analysis.3 Results agreed well for protein, fat, zinc, riboflavin, and palmitic acid. Results for iron were questionable: Lab A, 1.59 ± 0.14 (13); Lab B, 1.65 ± 0.56 (8); Lab C, 2.68 ± 0.78 (3) mg/100 g.
What is the difference between a false positive and a false negative?
Volatile compounds in human blood serum were measured by purge and trap gas chromatography/mass spectrometry. For quality control, serum was periodically spiked with a constant amount of 1,2-dichlorobenzene and the concentration (ng/g = ppb) was measured. Find the mean and standard deviation for
In Figure 5-6, the x-intercept is –2.89 mM and its standard deviation is 0.098 mM. Find the 90% and 99% confidence intervals for the intercept.Figure 5-6
A solution was prepared by mixing 5.00 mL of unknown element X with 2.00 mL of solution containing 4.13 µg of standard element S per milliliter, and diluting to 10.0 mL. The signal ratio in atomic absorption spectrometry was (signal from X)/(signal from S) = 0.808. In a separate experiment, with
An unknown sample of Ni2+ gave a current of 2.36 µA in an electrochemical analysis. When 0.500 mL of solution containing 0.028 7 M Ni2+ was added to 25.0 mL of unknown, the current increased to 3.79 µA.(a) Denoting the initial, unknown concentration as [Ni2+]i, write an expression for the final
An unknown sample of Ni2+ gave a current of 2.36 µA in an electrochemical analysis. When 0.500 mL of solution containing 0.028 7 M Ni2+ was added to 25.0 mL of unknown, the current increased to 3.79 µA.
Detection limit. In spectrophotometry, we measure the concentration of analyte by its absorbance of light. A low-concentration sample was prepared, and nine replicate measurements gave absorbances of 0.0047, 0.0054, 0.0062, 0.0060, 0.0046, 0.0056, 0.0052, 0.0044, and 0.0058. Nine reagent blanks
Detection limit. In spectrophotometry, we measure the concentration of analyte by its absorbance of light. A low-concentration sample was prepared, and nine replicate measurements gave absorbances of 0.0047, 0.0054, 0.0062, 0.0060, 0.0046, 0.0056, 0.0052, 0.0044, and 0.0058. Nine reagent blanks
Consider the linear calibration curve in Figure 4-13, which is derived from the 14 corrected absorbances in the shaded region at the right side of Table 4-7. Create a least-squares spreadsheet like Figure 4-15 to compute the equation of the line and the standard deviations of the parameters.
Consider the least-squares problem in Figure 4-11.(a) Suppose that a single new measurement produces a y value of 2.58. Find the corresponding x value and its uncertainty.(b) Suppose you measure y four times and the average is 2.58. Calculate the uncertainty based on four measurements, not
Using the linear calibration curve in Figure 4-13, find the quantity of unknown protein that gives a measured absorbance of 0.264 when a blank has an absorbance of 0.095.Figure 4-13 0.40 Unknown beyond linear region 0.35 0.30 Unknown in linear region 0.25 Quadratic 0.20 calibration curve 0.15 0.10
Excel LINEST function. Enter the following data in a spreadsheet and use LINEST to find slope, intercept, and standard deviations. Use Excel to draw a graph of the data and add a trendline. Draw error bars of ± sy on the points. X: 3.0 10.0 20.0 30.0 40.0 y: -0.074 -1.411 -2.584 -3.750 -5.407
Set up a spreadsheet to reproduce Figure 4-15. Add error bars: Follow the procedure on page 90. Use sy for the and + error.Figure 4-15 3 10 m 0.6154 1.3462" style="" class="fr-fic fr-dib"> A B D F G H 1 Least-Squares Spreadsheet 2 3 Highlight cells B10:C12 4 Type "= LINEST(C4:C7, B4:B7,TRUE, TRUE)
Repeat Problem 4-6 but use the values 50, 100, and 150 for the standard deviation. Superimpose all three curves on a single graph.Problem 4-6The equation for the Gaussian curve in Figure 4-1 iswhere x̅ is the mean value (845.2 h), s is the standard deviation (94.2 h), total bulbs = 4 768, and
The equation for the Gaussian curve in Figure 4-1 iswhere x̅ is the mean value (845.2 h), s is the standard deviation (94.2 h), total bulbs = 4 768, and hours per bar (= 20) is the width of each bar in Figure 4-1. Set up a spreadsheet like the one on the next page to calculate the coordinates of
Calibration curve. You can do this exercise with your calculator, but it is more easily done by the spreadsheet in Figure 4-15. In the Bradford protein determination, the color of a dye changes from brown to blue when it binds to protein. Absorbance of light is measured.Figure 4-15(a) Find the
Traces of toxic, man-made hexachlorohexanes in North Sea sediments were extracted by a known process and by two new procedures, and measured by chromatography.(a) Are the concentrations parts per million, parts per billion, or something else?(b) Is the standard deviation for procedure B
A reliable assay shows that the ATP (adenosine triphosphate) content of a certain cell type is 111 = mol/100 mL. You developed a new assay, which gave the following values for replicate analyses: 117, 119, 111, 115, 120 mol/100 mL (average = 116.4). Does your result agree with the known value at
Use the NORMDIST spreadsheet function to answer these questions about the brakes described in Exercise 4-C:(a) What fraction of brakes is expected to be 80% worn in less than 45 800 miles?(b) What fraction is expected to be 80% worn at a mileage between 60 000 and 70 000 miles?Table 4-1 Area |2|
Use Table 4-1 for this exercise. Suppose that the mileage at which 10000 sets of automobile brakes had been 80% worn through was recorded. The average was 62700, and the standard deviation was 10 400 miles.(a) What fraction of brakes is expected to be 80% worn in less than 40 860 miles?(b) What
Spreadsheet for standard deviation. Let’s create a spreadsheet to compute the mean and standard deviation of a column of numbers in two different ways. The spreadsheet here is a template for this exercise.(a) Reproduce the template on your spreadsheet. Cells B4 to B8 contain the data (x values)
For the numbers 116.0, 97.9, 114.2, 106.8, and 108.3, find the mean, standard deviation, range, and 90% confidence interval for the mean. Using the Grubbs test, decide whether the number 97.9 should be discarded.
Estimating uncertainty in Keeling’s CO2 measurements. The manometer in Box 3-2 has the following key uncertainties:Volume of large vessel: 5.01382 ± 0.0005 LVolume of small vessel: 3.7930 ± 0.0009 mLPressure: ± 0.03 mm Hg in ~ 400 mm HgTemperature: ± 0.03 K in ~300 KWhich factor has the
Why do we use quotation marks around the word true in the statement that accuracy refers to how close a measured value is to the “true” value?
Controlling the appearance of a graph. Figure 3-3 requires gridlines to read buret corrections. In this exercise, you will format a graph so that it looks like Figure 3-3. Follow the procedure in Section 2-11 to graph the data in the following table. For Excel 2007, insert a Chart of the type
Vernier scale. The figure below shows a scale found on instruments such as a micrometer caliper used for accurately measuring dimensions of objects. The lower scale slides along the upper scale and is used to interpolate between the markings on the upper scale. In (a), the reading (at the left-hand
Round each number to three significant figures:(a) 0.216 74(b) 0.216 5(c) 0.216 500 3
Round each number as indicated:(a) 1.236 7 to 4 significant figures(b) 1.238 4 to 4 significant figures(c) 0.135 2 to 3 significant figures(d) 2.051 to 2 significant figures(e) 2.005 0 to 3 significant figures
How many significant figures are there in the following numbers?(a) 1.903 0(b) 0.039 10(c) 1.40 × 104
Compute the molecular mass and its standard uncertainty for NH3. What is the percent relative uncertainty in molecular mass?
We have a 37.0 (± 0.5) wt% HCl solution with a density of 1.18 (± 0.01) g/mL. To deliver 0.050 0 mol of HCl requires 4.18 mL of solution. If the uncertainty that can be tolerated in 0.050 0 mol is ±2%, how big can the absolute uncertainty in 4.18 mL be?Caution: In this problem, you have to work
(a) How many milliliters of 53.4 (±0.4) wt% NaOH with a density of 1.52 (± 0.01) g/mL will you need to prepare 2.000 L of 0.169 M NaOH?(b) If the uncertainty in delivering NaOH is [1]0.01 mL, calculate the absolute uncertainty in the molarity (0.169 M). Assume there is negligible uncertainty in
How many milliliters of 53.4 (±0.4) wt% NaOH with a density of 1.52 (± 0.01) g/mL will you need to prepare 2.000 L of 0.169 M NaOH?(b) If the uncertainty in delivering NaOH is [1]0.01 mL, calculate the absolute uncertainty in the molarity (0.169 M). Assume there is negligible uncertainty in the
Write each answer with a reasonable number of figures. Find the absolute and percent relative uncertainty for each answer.(a) [12.41 (±0.09) ÷ 4.16 (± 0.01)] × 7.068 2 (± 0.000 4) = ?(b) [3.26 (±0.10) × 8.47 (± 0.05)] - 0.18 (± 0.06) = ?(c) 6.843 (± 0.008) × 104 ÷ [2.09 (± 0.04) - 1.63
The efficiency of a gas chromatography column is measured by a parameter called plate height (H, mm) which is related to the gas flow rate (u, mL/min) by the van Deemter equation: H = A + B/u + Cu, where A, B, and C are constants. Prepare a spreadsheet with a graph showing values of H as a function
The true volume of a 50-mL volumetric flask is 50.037 mL at 20°C. What mass of water measured (a) in vacuum and (b) in air at 20°C would be contained in the flask?
Which drying agent is more efficient, Drierite or phosphorus pentoxide?
What is the purpose of the trap in Figure 2-17 and the watchglass in Figure 2-20?Figure 2-17Figure 2-20 Gooch filter crucible To air -Rubber adaptor -Glass funnel To house vacuum Porous glass Gooch filter crucible Suction flask Trap
When is it preferable to use a plastic volumetric flask instead of a more accurate glass flask?
What do the symbols “TD” and “TC” mean on volumetric glassware?
The densities (g/mL) of several substances are: acetic acid, 1.05; CCl4, 1.59; S, 2.07; Li, 0.53; Hg, 13.5; PbO2, 9.4; Pb, 11.4; Ir, 22.5. From Figure 2-9, predict which substances will have the smallest and largest buoyancy corrections.Figure 2-9 1,003 1,002 Water 1,001 Sodium chloride Silver
Pentane (C5H12) is a liquid with a density of 0.626 g/mL near 25°C. Find the true mass of pentane when the mass in air is 14.82 g. Assume air density = 0.001 2 g/mL.
Why is the buoyancy correction equal to 1 in Figure 2-9 when the density of the object being weighed is 8.0 g/mL?Figure 2-9
After safety features and safety procedures in your laboratory have been explained to you, make a list of them.
What is the primary safety rule and what is your implied responsibility to make it work?
Reproduce the spreadsheet in Figure 2-23 and the graph in Figure 2-24.Figure 2-23Figure 2-24 A E F G H Calculating Density of H2O with Equation 2-4 (from the delightful book by Dan Harris) 3 1.00100 4 Constants: Temp (C) Density (g/mL) 1.00000 a0 = 0.99997 0.99900 6 0.99989 10 0.99970 0.99800 7 a1
Reproduce the spreadsheet in Figure 2-23 and the graph in Figure 2-24.Figure 2-24 Density of Water 1.000 0.998 0.996 - 0.994 0.992 10 20 30 40 Temperature (°C) Density (g/mL)
Water was drained from a buret between the 0.12- and 15.78-mL marks. The apparent volume delivered was 15.78 - 0.12 =15.66 mL. Measured in the air at 22°C, the mass of water delivered was 15.569 g. What was the true volume?
A solution of potassium permanganate (KMnO4) was found by titration to be 0.051 38 M at 24°C. What is the molarity when the lab temperature drops to 16°C?
A sample of ferric oxide (Fe2O3, density = 5.24 g/mL) obtained from ignition of a gravimetric precipitate weighed 0.296 1 g in the atmosphere. What is the true mass in vacuum?
What is the true mass of water if the measured mass in the atmosphere is 5.397 4 g? When you look up the density of water, assume that the lab temperature is(a) 15°C(b) 25°C.Take the density of air to be 0.001 2 g/mL and the density of balance weights to be 8.0 g/mL.
Describe how you would prepare approximately 2 L of 0.050 0 m boric acid, B(OH)3.
How many grams of boric acid, B(OH)3 (FM 61.83), should be used to make 2.00 L of 0.050 0 M solution? What kind of flask is used to prepare this solution?
What is the formal concentration (expressed as mol/L = M) of NaCl when 32.0 g are dissolved in water and diluted to 0.500 L?
Write the names and abbreviations for each of the prefixes from 10-24 to 1024. Which abbreviations are capitalized?
A solution of NaOH was standardized by titration of a known quantity of the primary standard, potassium hydrogen phthalateThe NaOH was then used to find the concentration of an unknown solution of H2SO4:(a) Titration of 0.824 g of potassium hydrogen phthalate required 38.314 g of NaOH solution to
Ascorbic acid (vitamin C, page 354) reacts with I-3 according to the equationStarch is used as an indicator in the reaction. The end point is marked by the appearance of a deep blue starch-iodine complex when the first fraction of a drop of unreacted I-3 remains in the solution.(a) Use atomic
A solution contains 12.6 ppm of dissolved Ca(NO3)2 (which dissociates into Ca2+ 2NO-3). Find the concentration of NO-3 in parts per million.
A 48.0 wt% solution of HBr in water has a density of 1.50 g/mL.(a) Find the formal concentration of HBr.(b) What mass of solution contains 36.0 g of HBr?(c) What volume of solution contains 233 mmol of HBr?(d) How much solution is required to prepare 0.250 L of 0.160 M HBr?
A solution with a final volume of 500.0 mL was prepared by dissolving 25.00 mL of methanol (CH3OH, density = 0.791 4 g/mL) in chloroform.(a) Calculate the molarity of methanol in the solution.(b) The solution has a density of 1.454 g/mL. Find the molality of methanol.
Showing 200 - 300
of 286
1
2
3
Step by Step Answers