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Physical Chemistry

Diffussion controlled electrolysis

Diffussion controlled electrolysis proceeds on (a) planar and (b) spherical electrode under the conditions: n = 1, C = 1 mM, A= 0.04 cm^2, D = 1.5x10^-5 cm^2/s. Calculate the current (i) in both cases at t = 0.5, 1, 3, 10 sec. How long can the electrolysis proceeed before the current at the spherical electrode exceeds that

Kinetics: Exchange Current Density

The symmetry factor Beta was determined to be 0.4 for an activation controlled Ag deposition process. At overpotential n = -0.400 V the current density was found to be j = -5.125 A/dm^2. What is the value of the exchange current density jo, and what will be the current density j [A/dm^2] at an overpotential of -0.003 V?

Lewis Structures, Hybrid orbital

1. Draw the Lewis structure for OF2 (small 2 at bottom) What are its electron-pair and molecular geometries? decribe the bonding in the molecule in terms of hybrid orbitals. 2. Draw the Lewis structure for C1F 2 + (small s at bottom and small + at top) What are its electron-pair and molecular geometries? decribe the bonding i

Potential difference

What will be the exact potential difference in the following concentration cells? a) Ag/Ag+ (0.1 M) // (0.01 M) Ag+/Ag b) Ag/Ag+ (0.000001 M) // (0.00001 M) Ag+/Ag Show step by step please

Calorimetry involving heat of solution of NaOH(s)

A lab experiment dealing with the properties of a coffee cup calorimeter was completed. One of the procedures involved measuring the temperature of 50mL water placed in a calorimeter for 3 minutes, and then adding NaOH(s) pellets and measuring the temperature for 4 more minutes. I have several temperature measurements, but I am

States of Matter

A meteorological balloon of radius 1.0M at sea level and 20 degrees C. At it's maximum altitude the radius of the balloon is 3.0M and the temperature is -20 degrees C. Calculate the pressure inside the balloon.

States of Matter

Ian eats too many mars bars. To try to get rid of the excess kJ's he exercises in the gym by using a weights machine which works by compressing a cylinder of gas. If a standard mars bar is approximately 1000kJ. Calculate the number of times Ian has to push the piston in the cylinder up and down to 'burn off' a mars bar. Assume

H2O yield in mL from Na2CO3 + 2HCl

I have worked this problem many different ways and cannot seem to set it up correctly. Na2CO3 + 2HCl => 2NaCl + CO2 + H2O I have 36.53g of sodium carbonate reacting with 32.94g of hydrchloric acid. I am trying to find how many mL of water are produced from this reaction.

Electrochemistry

1. a) A copper refining cell is operating with an electrolyte which contains 0.05 m Sn2+. At what concentration of Cu2+ will the tin start to plate out in preference to the copper? The cell temperature is 40°C. b) A polarization potential arises from a concentration difference between ions in the neighborhood of the el

Gas density calculations

A gas was found to have a densitiy of .08747 mg/ml at 17.0 degree C and a pressure of 76o torr. What is its molecular mass? What type of gas most likely is this?

Lasers and gas mixtures

A certain laser uses a gas mixture made up of 9.00 g HCL, 2.00 g H2, and 165.0 g Ne. What pressure is exerted by the mixture in a 75.0 L tank at 22 degree C? Which gas has the smallest partial pressure?

Rates and electrochemistry

1. Step 1: Cl2 ------ 2Cl (fast) Step 2: CHCl3 + Cl -------- CCl3 + HCl (slow) Step 3: CCl3 + Cl ------------CCl4 (fast) Identify the rate determining step, reaction intermediates and the experimental rate law (intermediates can not be in the rate law) 2. For the half-reaction XeF2(aq) +

Rates and electrochemistry

The numerical value of the rate constant for the gaseous reaction 2N2O5------- 4NO2+ O2 was found to be 5.8*10-4. The initial concetration of N205 was 1.00mol/L. Assuming all measurements are recorded in seconds, determine the tim required for the reation to be 60% complete if the reaction is second order

Thermodynamics

1. 5.30 moles of gas, initially at 25 degrees celcius and 5.00 atm pressure, was allowed to expand adiabatically( with no heat exchange between systen and surroundings) against a constant external pressure of 1.50 atm until the initial volume had trebled. The heat capacity of the gas was known to be 37.1 J/ degree celuius mol

show u VS T, S vs T, and V vs T for 1st order transition (discontinuous)

The two figures show Cp VS T for various transitions. I need to know what the graph would look like for: 1. u (internal energy) vs T 2. S (Entropy) vs T 3. and V vs T for a first order (discontinuous) transition. Extra Info: FOr the equilibrium phase transitions at constant T and P (temperature and pressure) t

Electrode Chemistry

An ammonium ion selective electrode responds to both NH4+ and H+, but not to NH3. (pKa=9.244 for NH4+) A) What pH conditions must be imposed to ensure the electode properly represents toe activity of NH4+ B) Why is the ionic strength an important factor when using this or any ISE? How can you compensate for this effect?

First-Order Reaction

In the study of a first-order reaction, A--->B, it is found that A/Ao=0.125 after one hour. The system initially consisted of 0.20 mole of a gaseous A at 25 degrees C and 1 atm. Calculate the initial rate of reaction in moles of A reacting per minute.

Steady State Assumption

For the following mechanism: N205------>k1<--------k2 N02 + N03 N0 + N03 ------>k3 2N02 Using the steady-state assumption, find the expression for dPN02/dt Note. The k1 is on top of the right pointing arow and k2 is below the left pointing arrow and the arrows are like they are in equilibriu

Percent by Mass

Determine the percent by mass of all the elements in the compound cobalt III acetate.

Chemistry

How would you prepare a liter of "carbonate buffer" at a pH of 10.10? Ka = 4.2 times ten to the negative 7(carbonic acid) Ka = 4.8 times ten to the negative 11(bicarbonate ion) It says the key to solving the problem is picking the correct Ka value. How do I know which one to work with?

Find Delta Smix, Delta Gmix, Delta Hmix, and Delta Vmix

Find delta Smix, delta Gmix, delta Hmix, and delta Vmix if 125 g of benzene and 25 g of naphthalene are mixed at 60 degrees C. Assume the solution to be ideal. The molecular weights of benzene and naphthalene are 78.12 g/mol and 128.19 g/mol respectively.

AP Chemistry Test Review: Gases

(See attached file for full problem description) --- 31. A sample of H2 gas occupies 615 mL at C and 575 mm Hg. When the gas is cooled, its volume is reduced to 455 mL and its pressure is reduced to 385 mm Hg. What is the new temperature of the gas? 54. Hydrogen can be made in the "water gas reaction." If you

Blending of Wines with Acid

I need some help with this question: Two wines are available for blending: One tank of 1000 L has a Titratable Acidity of 9.0 g/L and another tank containing 2000 L has a Titratable Acidity of 0.6 g/L. How much volume do you need to blend to make the 9.0 g/L Titatrable Acid wine equivalent to 7.2 g/L? What is the final volu