In: Chemistry
Calculate the pH for each of the following cases in the titration of 50.0 mL of 0.140 M HClO(aq) with 0.140 M KOH(aq).
(a) before addition of any KOH
(b) after addition of 25.0 mL of KOH
(c) after addition of 35.0 mL of KOH
(d) after addition of 50.0 mL of KOH
(e) after addition of 60.0 mL of KOH
In: Chemistry
1) The emission spectrum of a hollow cathode lamp for molybdenum was found to have a sharp peak at 313.3 nm as long as the lamp current was less than 50 mA. At higher currents, however, the peak developed a cup-like crater at its maximum. Explain. 2) Why does the cathode of the hollow cathode lamp have a cylindrical shape? Why is an element lamp required as the source for AA? Which copper line was used for analysis of copper in the CAM experiment?
In: Chemistry
Suppose that the microwave radiation has a wavelength of 12.4 cm . How many photons are required to heat 285 mL of coffee from 25.0 ∘C to 62.0 ∘C? Assume that the coffee has the same density, 0.997 g/mL , and specific heat capacity, 4.184 J/(g⋅K) , as water over this temperature range.
Express the number of photons numerically.
In: Chemistry
4. Given the following half reaction
Fe(OH)3 (s) + e- +3H+ çè Fe2+ + 3H2O log K = 15.8
(6 pts) The Grinnell formation in Glacier N.P., formed from ocean sediments, is typified by contrasting gray and red colors, yet the total Fe (iron) concentration remains constant throughout the rock. Can you explain this color variation? (Hint: iron turns red as it “rusts”).
In: Chemistry
Indicate the concentration of each ion present in the solution formed by mixing
44.0 mL of 0.100 M Na2SO4 and 25.0 mL of 0.200 M KCl
3.80 g KCl in 75.0 mL of 0.230 M CaCl2 solution. Assume that the volumes are additive.
In: Chemistry
A battery is constructed based on the oxidation of magnesium and the reduction of Cu2+. The initial concentrations of Mg2+ and Cu2+ are 1.1×10−4 M and 1.6 M , respectively, in 1.0-liter half-cells. What is the initial voltage of the battery? Answer:2.8. What is the voltage of the battery after delivering 5.0 A for 8.0 h ? How long can the battery deliver 5.0 A before going dead? Please show all step thank you
In: Chemistry
|
Suppose that a catalyst lowers the activation barrier of a reaction from 122 kJ/mol to 59 kJ/mol . |
Part A By what factor would you expect the reaction rate to increase at 25 ∘C? (Assume that the frequency factors for the catalyzed and uncatalyzed reactions are identical.) |
In: Chemistry
A small gas turbine uses C8H18(l) for fuel and it
enters the combustion
chamber at 25◦C whereas air coming from the high pressure stage is
at 287◦C . The products of combustion leave the combustion chamber
at 1167◦C . The fuel is injected at a rate of 0.95 kg/min where it
is mixed and burned with 400 % excess air. An analysis of
combustions reveals that all the hydrogen in the fuel burns to H2O
but only 90% of the carbon burns to CO2, with remaining 10% forming
CO. Determine:
(a) the phase of the water in the products
(b) the mass flow rate of the air
(c) the rate of heat transfer from the combustion chamber.
In: Chemistry
complete and balance the net ionic equations for reactions that would occur:
Zn(s)+Mg2+(aq)--->
Zn(s)+Cu2+(aq)---->
Zn(s)+H+(aq)----->
Mg(s)+Zn2+(aq)----->
Mg(s)+Cu2+(aq)--->
Mg(s)+H+(aq)---->
Cu(s)+Zn2+(aq)---->
Cu(s)+Mg2+(aq)---->
Cu(s)+H+(aq)----->
In: Chemistry
In what form (Fe3+ or FeSCN-) could iron be determined by visible spectroscopy?
In: Chemistry
As temperature increases does a compounds vapor pressure change? Does its boiling point change? Explain
In: Chemistry
use daltons law to calculate pressures in mixtures of gases.
any examples on this review? please provide a problem with steps leading to a solution to help me review, thanks!
In: Chemistry
Why might percent recovery be low during extractions?
A mixture that contains benzoic acid, 4-chloroaniline and naphthalene. The 4-chloroaniline is separated first by extraction with hydrochloric acid.Since no phenolic compound is present in this mixture, two extractions with base solution are not required; thus, the benzoic acid could be separated from the neutral compound by extraction with either aqueous sodium bicarbonate or aqueous sodium hydroxide solution. We have chosen to extract the acidic compound into the aqueous layer using sodium hydroxide.
My percent recovery for 4-chloroaniline= 13% Benzoic acid: 30.2% Naphthalene: 25.2%
In: Chemistry
Use bond enthalpies to estimate
a) the enthalpy of the anaerobic breakdown of glucose to lactic acid in cells that are starved of oxygen, C6H12O6(aq) → 2 CH3CH(OH)COOH(aq),
b) the enthalpy of combustion of glucose. Ignore the contributions of enthalpies of fusion and vaporization.
In: Chemistry