GGR107H1 Chapter Notes -Loam, Red, Ion

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fuchsiamammoth394

18 May 2012

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Central case: mer bleue: a bog of international significance. Mer bleue conservation area is 35 km^2 of provincial land east of ottawa. It hosts a number of unusual plants species such as cottongrass, cattails and tamarack. Peatland can store carbon and reduce amount of greenhouse gas from methane and carbon dioxide. Storage of carbon in peat depends on the balance between net primary production and decomposition. Peatland carbon study (pcars) was initiated by a group of canadian. Researchers involved in the project have an interest in the ecosystems structure and function. Scientists are building scientific instruments to measure the flux in soil. Soil has half of the minerals found on this planet. The formation of soil is important for primary succession. Parent material: is the base geological material in a particular location ex. The processes that create soil include weathering, erosion and deposition and decomposition of organic matter. Weathering: the physical breakdown of rocks and minerals.

Related Questions

Fill in the nine gaps in this table.
Symbol B
Protons 19
Neutrons 20
Electrons 18
Mass number 11 40

Identify the unknown particle (X) in the following equations fornuclear decay, and state whether each process is alpha decay, betadecay, or gamma decay. (Type your answer according to this format:4 2 He represents . Use gamma to enter ?.)
(a) ? X + -
X =

(b) ? + X
X =

(c) ? + X
X =

Actinium-225 () undergoes alpha decay.
(a) Write the equation. (Enter the mass number in the first raisedbox, the atomic number in the second lower box, and the element,with charge if necessary, in the third box.)
? + He

(b) The daughter formed in part (a) undergoes beta decay. Write theequation. (Enter the mass number in the first raised box, theatomic number in the second lower box, and the element, with chargeif necessary, in the third box.)
? + e

Classify each of the following materials as an element, compound,heterogeneous mixture, or homogeneous mixture.
(a) concrete
element
compound
heterogeneous mixture
homogeneous mixture

(b) clear apple juice
element
compound
heterogeneous mixture
homogeneous mixture

(c) nitrogen
element
compound
heterogeneous mixture
homogeneous mixture

(d) ozone
element
compound
heterogeneous mixture
homogeneous mixture

Refer to the figure below. Find the approximate solubility (g/100 gwater) of sugar at 20Â°C.
g/100 g of water

Give the symbol for each of the following elements.
(a) lead

(b) sodium

(c) oxygen

Give the name of each element.
(a) Cu

(b) Bi

(c) Ti

Volcanoes emit much hydrogen sulfide gas, H2S, which reacts withthe oxygen in the air to form water and sulfur dioxide, SO2. Every53 tons of H2S reacts with 75 tons of oxygen and forms 28 tons ofwater. How many tons of SO2 are formed?

An antacid tablet weighing 0.939 g contained calcium carbonate asthe active ingredient, in addition to an inert binder. When an acidsolution weighing 56.233 g was added to the tablet, carbon dioxidegas was released, producing a fizz. The resulting solution weighed56.954 g. How many grams of carbon dioxide were produced?

Calculate (to the nearest 0.1 u) the formula mass of thesecompounds.
(a) sodium phosphate, Na3PO4
u

(b) methane, CH4
u

(c) silver cyanide, AgCN
u

Calculate (to the nearest 0.1 u) the formula mass of thesecompounds.
(a) silver carbonate, Ag2CO3
u

(b) calcium bromide, CaBr2
u

(c) magnesium hydroxide, MgOH
u

Balance these chemical equations. (Use the lowest possiblecoefficients.)
(a) O2 + N2H4 ? H2O2 + N2

(b) Sr + H2O ? Sr(OH)2 + H2

(c) NH3 + O2 ? N2 + H2O

(d) Al + Fe3O4 ? Al2O3 + Fe

(e) Fe(OH)2 + O2 + H2O ? Fe(OH)3

(f) Pb(NO3)2 ? PbO + NO2 + O2

(a) Calcium and chlorine react to give calcium chloride in acombination reaction. Write and balance the equation. (Type youranswer using the format CO2 for CO2. Use the lowest possiblecoefficients.)

Ca + ?

(b) Heating decomposes Na2CO3 to sodium oxide and carbon dioxide.Write and balance the equation. Type your answer using the formatCO2 for CO2. Use the lowest possible coefficients.)

Na2CO3 ? + CO2

Write and balance the reaction for the complete combustion ofmethanol, CH3OH. (Type your answer using the format CO2 for CO2.Use the lowest possible coefficients.)

3. 3 Stratosphere-troposphere exchange

The rate of exchange of air between the troposphere and thestratosphere is critical for determining the potential of variouspollutants emitted from the surface to reach the stratosphere andaffect the stratospheric ozone layer. One of the first estimates ofthis rate was made in the 1960s using measurements of strontium-90(90Sr) in the stratosphere. Strontium-90 is a radioactive isotope(half-life 28 years) produced in nuclear explosions. It has nonatural sources. Large amounts of 90Sr were injected into thestratosphere in the 1950s by above-ground nuclear tests. Thesetests were banned by international treaty in 1962. Following thetest ban the stratospheric concentrations of 90Sr began to decreaseas 90Sr was transferred to the troposphere. In the troposphere,90Sr is removed by wet deposition with a lifetime of 10 days (bycontrast there is no rain, and hence no wet deposition, in thestratosphere). An intensive stratospheric measurement network wasoperated in the 1960s to monitor the decay of 90Sr in thestratosphere. We interpret these observations here using a 2-boxmodel for stratosphere-troposphere exchange with transfer rateconstants kTS and kST (yr-1) between the tropospheric andstratospheric reservoirs. The reservoirs are assumed to beindividually well-mixed.

Let mS and mT represent the masses of 90Sr in the stratosphere andin the troposphere respectively. Observations of the decrease inthe stratospheric inventory for the period 1963-1967 can be fittedto an exponential mS(t) = mS(0)exp(-kt) where k = 0.77 yr-1.

1. Write mass balance equations for mS and mT in the 1963-1967period.

2. Assuming that transfer of 90Sr from the troposphere to thestratosphere is negligible (we will verify this assumption later),show that the residence time of air in the stratosphere is tS =1/kST = 1.3 years.

3. Let m'T and m'S represent the total masses of air in thetroposphere and the stratosphere, respectively. Show that theresidence time of air in the troposphere is tT = tS (m'T/m'S) = 7.4years. Conclude as to the validity of your assumption in question2.

4. Hydrochlorofluorocarbons (HCFCs) have been adopted asreplacement products for the chlorofluorocarbons (CFCs), which werebanned by the Montreal protocol because of their harmful effect onthe ozone layer. In contrast to the CFCs, the HCFCs can be oxidizedin the troposphere, and the oxidation products washed out byprecipitation, so that most of the HCFCs do not penetrate into thestratosphere to destroy ozone. Two common HCFCs have trade namesHCFC-123 and HCFC-124; their lifetimes against oxidation in thetroposphere are 1.4 years and 5.9 years, respectively. There are noother sinks for these species in the troposphere. Using our 2-boxmodel, determine what fractions of the emitted HCFC-123 andHCFC-124 penetrate the stratosphere.

Theory: Topics that you should be familiar with are: significantfigures, least count and estimated fraction, systematic and randomerrors, accuracy versus precision, percent difference and percenterror. These topics should have been covered in class already (orperhaps in an introduction to the lab manual or in a handout). Itis assumed that the instructor has discussed how to use the massbalance, etc.
Introduction: The goal of section I of this experiment is tomeasure (to the correct least count and estimated fraction) andcalculate (to the correct number of significant figures) thedensity of a metal ball and compare it to a table of accepteddensities (?=7.8x103 kg/m3).
To accomplish this goal keep in mind that: ? = m/V and Vsphere =(4/3) p r3
In the space below create a data table, show your calculations indetail, and compare your measured answer to accepted values givenabove. (Would you calculate a percent error or a percentdifference?)
1
II. Is g (the acceleration due to gravity) a constant? If so, whatis it?
1) SetuptheFree-FallApparatusasdemonstratedbytheinstructor.
2)MeasurethetimeittakesforthemetalballtofallthroughthesuggesteddisplacementsshowninDataTable 1. Be sure to do 4 trials for each fall and take the averageof your time and displacement. For each trial measure thedisplacement and record your results as precisely as possible. Becareful how you measure the displacement!
Data Table 1
Displacement (meters) Time
Trial 1
___.40___ m .281 s
______.40_ m .284 s
___.40____ m .283 s
____.40___ m .285 s
Average Displacement =.40 m Average time .0285 s
Trial 2
____.60___ m .357 s
____.60___ m .358 s
_____.60__ m .347 s
____.60___ m .347 s
Time (seconds)
Average Displacement = .60 Average Time = .352
Trial3
_.80____ m .402 s
_.80____ m .401 s
_.80______ m .402 S
_.80___ m .401 s
Average Displacement = .80 m Average Time =.401 s

Trial4
__ 1.00____ m .454 s
___1.00____ m .453 s
___1.00____ m .463 s
___1.00____ m .453 s
Average Displacement = 1.00 m Average Time =.455 s
3)PlotDisplacement(usetheaveragedisplacement)asafunctionofTime(usetheaveragetime)usingacomputer software that you know the best. (Does Displacement orTime go on the âverticalâ (or y) axis? Make sure that you label theaxes of your graph properly and give the graph a descriptivetitle.), Please include (0,0) point.
4)UsetheCurveFitFunctiontotrytofindthecurvethatistheclosestfitforthegraph.Whichofthefollowing curve types gives the best fit? Try each to findout.
a) linear fit? b) quadratic (power 2)? c) exponential? d) Power?
The curve with the correlation coefficient (R) closest to 1 has theclosest fit. (e.g. 0.997 is better than 0.956)
5)Printthecurvewiththeclosestfit(oneforeachmemberofthelabgroup).Besureyourgraphincludesthe equation for your fit.
6)Canyoudeterminetheexperimentalaccelerationofgravityfromthisgraph?Explainhowandshowyourwork.
7)Ifalinearfunctionisnotthebestfitofyourplotfromstep3),howwouldyouplotdisplacementandtimeso that the resulting plot is linear? Explain. (Ask your instructorfor a hint if you are not sure of what to do, but be sure to thinkabout it for a while before you ask.)
3
8)Printacopyofthegraphforeachlabpartnershowingalinearfittoyourdataandproperlylabeledaxes.
9)Canyoudeterminetheexperimentalaccelerationduetogravityfromthisgraph?Explainandshowyourwork.
10) How do your experimental values of âgâ compare with theaccepted value (g = 9.80 m/s2) for the acceleration of gravity?Give a mathematical comparison using what you learned aboutmeasurements previously. (Show work)
4
Question and further procedures
1. What is the greatest source of error in performing theexperiment? Is this error random or systematic? Explain.
2. At this point you should have calculated g in two different ways(A quadratic graph, and a linear graph). Which technique do youthink is best? Do all two techniques give the same answer? If not,which technique do you think has the most error?
3. How might you modify your procedures to determine whether or notg depends on the mass of the falling object? Do the experiment andcalculate g using your favorite technique.

GGR107H1 Chapter Notes -Loam, Red, Ion

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