When 22.0 mL of a 5.89×10-4 M sodium hydroxide solution is combined with 12.0 mL of a 5.49×10-4 M silver fluoride solution does a precipitate form? (yes or no) For these conditions the Reaction Quotient, Q, is equal to
In: Chemistry
An X-ray photon with a wavelength of 0.979 nm strikes a surface. The emitted electron has a kinetic energy of 984 eV.
What is the binding energy of the electron in kJ/mol? [Note that KE = 12mv2 and 1 electron volt (eV) = 1.602×10−19J.]
In: Chemistry
An adiabatic tank contains 120 kg of liquid water initially at 70 °C. The water within the tank is utilized to quench (cool) a 15 kg steel block initially at 300 °C. The steel block is dropped into the tank, and after some time the steel block and the water in the tank reach thermal equilibrium.
Determine the total entropy change during the quenching process.
Specific heat of steel : Csteel= 0.50 kJ/kg*K.
Specific heat of water : Cwater= 4.18 kJ/kg*K
In: Chemistry
A 0.4713 g sample of pewter, containing tin, lead, copper, and zinc, was dissolved in acid. Tin was precipitated as SnO2·4H2O and removed by filtration. The resulting filtrate and washings were diluted to a total volume of 250.0 mL. A 15.00 mL aliquot of this solution was buffered, and titration of the lead, copper, and zinc in solution required 35.63 mL of 0.001504 M EDTA. Thiosulfate was used to mask the copper in a second 20.00 mL aliquot. Titration of the lead and zinc in this aliquot required 34.75 mL of the EDTA solution. Finally, cyanide was used to mask the copper and the zinc in a third 25.00 mL aliquot. Titration of the lead in this aliquot required 26.61 mL of the EDTA solution. Determine the percent composition by mass of each metal in the pewter sample.
In: Chemistry
The initial rates listed in the following table were measured for the reaction between nitrogen dioxide and carbon monoxide that occurs in engine exhaust.
NO2(g)+CO(g)→NO(g)+CO2(g)NO2(g)+CO(g)→NO(g)+CO2(g)
| Experiment | Initial [NO2][NO2] | Initial [CO][CO] | Initial Reaction Rate (M/sM/s) |
| 1 | 0.100 | 0.100 | 5.00×10−35.00×10−3 |
| 2 | 0.150 | 0.100 | 1.13×10−21.13×10−2 |
| 3 | 0.200 | 0.200 |
2.00×10−22.00×10−2 |
What is the value of the rate constant and its units?
Express your answer to three significant figures and include the appropriate units.
In: Chemistry
Which of these has the lower concentration of hydrogen ions: 0.1 M H2SO4, 0.1 M HCl, CaCO3, or pure water?
In: Chemistry
How many liters of water have fallen on 1 hectare of land if 2.5
inches of water fell
during a rain storm? Give your answer in the correct number of
significant digits
In: Chemistry
Show with calculations whether a precipitate will form if: (a) 30.0 ml of 0.0024 M AgNO3 is mixed with 70.0 ml of 0.0036 M NaCl. (b) a solution that is 0.30 M with respect to HCl and 0.01 M with respect to Fe2+ is saturated with H2S (i.e. 0.10 M H2S). For FeS, Ksp = 3.7x10-19. Ksp for AgCl = 1.7x10-10.
In: Chemistry
1) Draw the skeletal structures of the 3 products formed from
CH4 and Cl in free radical reactions.
1a) Draw the skeletal structure of the major monohalogenated
organic product when cyclohexane reacts with Br in the presence of
light and heat.
1b)Draw the skeletal structure of the major monohalogenated organic
product when 2,2,4-trimethylhexane is treated with Br in the
presence of light and heat.
In: Chemistry
1. A solution contains 1.43×10-2 M
sodium phosphate and
6.22×10-3 M potassium
hydroxide.
Solid aluminum nitrate is added slowly to this
mixture.
What is the concentration of hydroxide ion when
phosphate ion begins to precipitate?
[hydroxide] = M
2.A solution contains 9.99×10-3 M
calcium nitrate and
1.06×10-2 M barium
acetate.
Solid sodium fluoride is added slowly to this
mixture.
What is the concentration of calcium ion when
barium ion begins to precipitate?
[Ca2+] = M
3.A solution contains 1.19×10-2 M
potassium phosphate and
1.12×10-2 M ammonium
sulfide.
Solid zinc acetate is added slowly to this
mixture.
What is the concentration of sulfide ion when
phosphate ion begins to precipitate?
[sulfide] = M
KSPS=PbBr26.3 × 10-6
AgBr3.3 × 10-13CarbonatesBaCO38.1 ×
10-9
CaCO33.8 × 10-9
CoCO38.0 × 10-13
CuCO32.5 × 10-10
FeCO33.5 × 10-11
PbCO31.5 × 10-13
MgCO34.0 × 10-5
MnCO31.8 × 10-11
NiCO36.6 × 10-9
Ag2CO38.1 × 10-12
ZnCO31.5 × 10-11ChloridesPbCl21.7
× 10-5
AgCl1.8 × 10-10ChromatesBaCrO42.0 ×
10-10
CaCrO47.1 × 10-4
PbCrO41.8 × 10-14
Ag2CrO49.0 ×
10-12CyanidesNi(CN)23.0 ×
10-23
AgCN1.2 × 10-16
Zn(CN)28.0 × 10-12FluoridesBaF21.7
× 10-6
CaF23.9 × 10-11
PbF23.7 × 10-8
MgF26.4 × 10-9HydroxidesAgOH2.0 ×
10-8
Al(OH)31.9 × 10-33
Ca(OH)27.9 × 10-6
Cr(OH)36.7 × 10-31
Co(OH)22.5 × 10-16
Cu(OH)21.6 × 10-19
Fe(OH)27.9 × 10-15
Fe(OH)36.3 × 10-38
Pb(OH)22.8 × 10-16
Mg(OH)21.5 × 10-11
Mn(OH)24.6 × 10-14
Ni(OH)22.8 × 10-16
Zn(OH)24.5 × 10-17IodidesPbI28.7 ×
10-9
AgI1.5 × 10-16OxalatesBaC2O41.1 ×
10-7
CaC2O42.3 × 10-9
MgC2O48.6 ×
10-5PhosphatesAlPO41.3 ×
10-20
Ba3(PO4)21.3 ×
10-29
Ca3(PO4)21.0 ×
10-25
CrPO42.4 × 10-23
Pb3(PO4)23.0 ×
10-44
Ag3PO41.3 × 10-20
Zn3(PO4)29.1 ×
10-33SulfatesBaSO41.1 ×
10-10
CaSO42.4 × 10-5
PbSO41.8 × 10-8
Ag2SO41.7 × 10-5SulfidesCaS8 ×
10-6
CoS5.9 × 10-21
CuS7.9 × 10-37
FeS4.9 × 10-18
Fe2S31.4 × 10-88
PbS3.2 × 10-28
MnS5.1 × 10-15
NiS3.0 × 10-21
Ag2S1.0 × 10-49
ZnS2.0 × 10-25SulfitesBaSO38.0 ×
10-7
CaSO31.3 × 10-8
Ag2SO31.5 × 10-14
In: Chemistry
2. Describe how you would prepare 100ml of 0.08 M sulfuric acid [H2SO4] from an 18 M concentrated sulfuric acid stock solution.
3. Describe how you would prepare 50 ml of 0.2 M potassium iodate [KIO3] dissolved in the 0.08 M sulfuric acid [H2SO4] that you have prepared above.
4. Describe how you would prepare 25 ml of 3.6 M hydrogen peroxide [h2O2] from a 30% (w/w) stock H2O2 solution (
5. Describe how you would prepare 50 ml of a 3% (w/v) soluble starch solution in water.
Molecular weights:
Malonic acid: 104.6
Manganese sulfate: 169.01
Potassium iodate: 214
Hydrogen peroxide: 34.01
In: Chemistry
A. Starting with 500 g of N2 and 500 g of H2 how much
NH3 can you form? And how much of the excess reagent ( N2 or H2)
remains (eg. is left over) after the reaction goes to
completion?
B. Starting with 50 g of sulfuric acid and 40 g of baking soda, how
much sodium sulfate is produced?
C. Based on the information in 6d above, how much of
the excess reactant remains after the reaction has gone to
completion?
In: Chemistry
A student seeks to neutralize 225mL of a 0.0369M sodium bicarbonate solution by addition of 0.222M sulfuric acid solution according to the following reaction: H2SO4(aq)+ NaHCO3(aq)---> Na2SO4(aq)+ H2O(l)+ CO2(g).
A.) Classify the reaction
B.) To neutralize the sodium bicarbonate, how many mL of sulfuric acid solution does the student need to add?
C.) How many grams of carbon dioxide gas is formed during the neutralization?
D.) What is the molarity of the sodium sulfate produced following the neutralization?
In: Chemistry
ZnCl2 (aq) + Al (s) ---- Zn(s) + AlCl3 (aq)
[Al3+] = 0.8 M [Zn2+] = 1.3M
Zn2+(aq) +2e- ---Zn(s) -0.76V
Al3+(aq) + 3e- --- Al (s) -1.66V
Balance the equation above.
Give the equation for the reaction quotient(Q) and solve for it. Are there units for (Q)?
Solve for the standard potential for the cell (EO cell) at 295K. First give equation.
Solve the Nernst equation for this cell at 295K.
In: Chemistry
A student researcher performed a chromatographic separation of caffeine and aspartame with methanol as the mobile phase using a C–18 column. The retention times for methanol (tm) , caffeine (tc) , and aspartame (ta) were 41.8 s , 96.3 s , and 143.8 s , respectively.
What is the selectivity factor (relative retention), α , for this column?
α=
Calculate the hypothetical retention times for caffeine and aspartame if their retention factors were reduced by 28.0% . Assume the mobile phase retention time (tm=41.8 s) remains constant.
tcaffeine=
staspartame=
Select the statements that correctly describe the outcome if the partition coefficient for caffeine (Kc) were to decrease.
The retention time of caffeine would increase.
The retention time of caffeine would decrease.
Caffeine would spend a greater amount of time in the mobile phase.
The retention factor of caffeine would decrease.
The retention factor of caffeine would increase.
The retention time and retention factor of caffeine would not change.
In: Chemistry