Top fuel dragsters and funny cars burn nitromethane as fuel
according to the following balanced combustion equation:
2CH3NO2(l)+3/2O2(g)→2CO2(g)+3H2O(l)+N2(g)2CH3NO2(l)+3/2O2(g)→2CO2(g)+3H2O(l)+N2(g)
The standard enthalpy of combustion for nitromethane is
−709.2kJmol−1−709.2kJmol−1.
Calculate the standard enthalpy of formation
ΔH∘fΔHf∘ for nitromethane.
ΔH∘fΔHf∘ ( kJmol−1kJmol−1 )
CO2(g)CO2(g) -393.5
H2O(l)H2O(l) -285.8
Express your answer using one decimal place.
In: Chemistry
Iodine clock reaction lab
2I-(aq) + S2O82-(aq)à I2(aq) + 2SO42- (aq)
Rate=k[I-]x[S2O82-]y
I need to calculate the initcial concentrations of I- and S2O8^2- then use that to calculate the reaction rate M/sec and the k value.
|
Run Number |
3% Starch |
0.012 Na2S2O3 mL |
0.20 M KI mL |
0.20 M KNO3 mL |
0.20 M (NH4)2SO4 mL |
0.20 M (NH4)2S2O8 mL |
Total= 2 mL |
Time sec |
|
1 |
2 drops |
0.200 |
0.800 |
0.200 |
0.400 |
0.400 |
2.00 |
35.75 |
|
2 |
2 drops |
0.200 |
0.400 |
0.600 |
0.400 |
0.400 |
2.00 |
109.72 |
|
3 |
2 drops |
0.200 |
0.200 |
0.800 |
0.400 |
0.400 |
2.00 |
218.65 |
|
4 |
2 drops |
0.200 |
0.400 |
0.600 |
0.00 |
0.800 |
2.00 |
33.31 |
|
5 |
2 drops |
0.200 |
0.400 |
0.600 |
0.600 |
0.200 |
2.00 |
219.18 |
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Determine the pH of a solution that is 1.85% NaOH by mass. Assume that the solution has density of 1.01 g/mL.
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Calculate how many milliliters of 0.663 M KOH should be added to 5.00 g of MOBS (see Table 8-2) to give a pH of 7.40. pKa=7.6. molecular weight=123.29
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A- Calculate the pH at equilibrium point in the titration of 50mL of 0.1M HC2H3O2 with 0.16M NaoH. Ka=1.8^-5
B--Calculate the pH if 35mL of 0.025M HCl is added to 30mL of 0.030M NH3. Kb=1.8^-5
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The excess Gibbs energy of solutions of methylcyclohexane (MCH)
and tetrahydrofuran (THF) at 303.15 K was found to fit the
expression
G E = RTx(1- x)[0.4857 – 0.1077(2x -1) + 0.0191(2x – 1)2 ]
where x is the molar fraction of the methylcyclohexane. Calculate the Gibbs energy of mixing when a mixture of 1.00 mol of MCH and 3.00 mol of THF is prepared.
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Calculate the mass of carbon gas produced if 6.000g of K2CO3 reacts with 10.00ml of 2.00M HNO3 identify the limiting reagent as indicated a) if the amount of carbon dioxide collected is part a is 0.3542g, calculate the percent yield for the rection b) if the 0.3542g of carbon dioxide were collected at STP (0C and 1 atm), calculate th volumen of gas collected
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NH2-
HSO4-
OH-
NH3
H2O
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Please explain in clear words. Thanks
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8) Given the following equation, C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O(g) ΔG°rxn = -2074 kJ
Calculate ΔG°rxn for the following reaction.
21 CO2(g) + 28 H2O(g) → 7 C3H8(g) + 35 O2 g)
A) +14518 kJ B) -2074 kJ C) -14518 kJ D) -296 kJ E) +2074 kJ
22) Given the following equation, C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O(g) ΔG°rxn = -2074 kJ
Calculate ΔG°rxn for the following reaction.
7 C3H8(g) + 35 O2(g) → 21 CO2(g) + 28 H2O(g)
A) -14518 kJ B) +2074 kJ C) -2074 kJ D) -296 kJ E) +14518 kJ
29) Given the following equation, H2O(g) + CO(g) → H2(g) + CO2(g) ΔG°rxn = -28.6 kJ
Calculate ΔG°rxn for the following reaction.
5 H2(g) + 5 CO2(g) → 5 H2O(g) + 5 CO(g)
A) +143.0 kJ B) -28.6 kJ C) -143.0 kJ D) +5.72 kJ E) -5.72 kJ
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(c) What is the pKa of the acid?
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What is the potential of a cell made up of Zn|Zn2+ and Cu|Cu2+ half-cells at 25o C if [Zn2+] = 0.25 M and [Cu2+] = 0.15 M?
(Answer should be E = +1.09 V but I need to know how to get to that)
In: Chemistry