what are the arrhenius definitions for an acid and base? give a chemical equation to demonstrate a strong acid and a weak acid
In: Chemistry
3. You are hard at work, setting up the apparatus to separate a 40:60 mixture of diethyl ether and toluene by simple distillation. Just as you are getting ready to begin the experiment, your lab partner mistakenly adds a small amount of sodium sulfate into the distillation flask. Would simple distillation still be appropriate or should you switch to fractional distillation? Explain.
In: Chemistry
Phosphoric acid H3PO4 is manufactured by treating mineral phosphates with concentrated sulfuric acid H2SO4. A typical phosphate mineral, Ca5(PO4)3F, reacts with sulfuric acid as shown by the equation:
Ca5(PO4)3F
+
5H2SO4
3H3PO4
+
5CaSO4·2H2O
+ HF
If 5.00 tons of this mineral is treated with 6.00 tons of sulfuric
acid to produce 2.70 tons of
phosphoric acid, what is the percent yield of phosphoric acid?
In: Chemistry
I am having problems with variables on both sides. I get most of the concepts but I need help with adding fractions into the equations.
In: Chemistry
Sketch the overlap of orbitals between the HOMO and LUMO that would result in the formation of the preferred product. (anthracene and maleic anhydride diels-alder reaction)
In: Chemistry
For a parallel reaction A goes to B with rate constant k1 and A goes to C with rate constant k2, you determine that the activation energies are 24.6 kJ/mol for k1 and 116.4 kJ/mol for k2. If the rate constants are equal at a temperature of 318 K, at what temperature (in K) will k1/k2 = 2?
In: Chemistry
what is the origin of the variety in the properties of polyurethanes
In: Chemistry
2NO(g) + Br2(g) 2NOBr(g) A reaction mixture was found to contain 4.70×10-2 moles of NO(g), 4.02×10-2 moles of Br2(g) and 9.28×10-2 moles of NOBr(g), in a 1.00 Liter container. Indicate True (T) or False (F) for each of the following: Indicate True (T) or False (F) for each of the following:
1. In order to reach equilibrium NOBr(g) must be produced.
2. In order to reach equilibrium Kc must decrease.
3. In order to reach equilibrium NO must be produced.
4. Qc is less than Kc.
5. The reaction is at equilibrium. No further reaction will occur.
In: Chemistry
A mixture of CH4(g) and C2H6(g) has a total pressure of 0.55 atm . Just enough O2(g) is added to the mixture to bring about its complete combustion to CO2(g) and H2O(g). The total pressure of the two product gases is found to be 2.3 atm . Assuming constant volume and temperature, find the mole fraction of CH4 in the mixture. Please type out answer step by step. Thank you!
In: Chemistry
10. Calculate q, w, ∆U, and ∆H when 50 g of O2(g) is heated at a constant pressure of 1 bar from 50 ºC to 200 ºC. Note: The constant volume heat capacity of O2 is 21.1 J mol-1 K-1.
In: Chemistry
1. Determine the pH of the buffer solution that is prepared by mixing 867 mL of 0.0403 M HEPES−H (C8H18N2O4S ) to 627 mL of 0.120 M HEPES (C8H17N2O4S− ). Assume the 5% approximation is valid. Report your answer to 2 decimal places.
2. Determine the pH of the HEPES−H/HEPES buffer solution after the addition of 21.2 mL of 2.89 M solution of hydrochloric acid to the existing buffer solution. Assume the 5% approximation is valid.
In: Chemistry
A pure gold ring and pure silver ring have a total mass of 15.4 g . The two rings are heated to 68.0 ∘C and dropped into a 13.0 mL of water at 21.5 ∘C. When equilibrium is reached, the temperature of the water is 23.7 ∘C.
Part A
What is the mass of gold ring? (Assume a density of 0.998 g/mL for water.)
Express your answer to two significant figures and include the appropriate units.
|
|
|||
| mAu= |
Part B
What is the mass of silver ring? (Assume a density of 0.998 g/mL for water.)
Express your answer to two significant figures and include the appropriate units.
|
|
|||
| mAg= |
In: Chemistry
In: Chemistry
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 |
In: Chemistry