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Physical Chemistry

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


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.


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

Calculations with Ideal Gas Laws

I need to find a simple way to convert gases expressed as mol % to volume percent. Pressure and temperature are constant. For example, what volume percent would water vapour be if given as 1.52 mol %?

Heat Capacity of a Gas

The heat capacity of a gas is given by Cp=a+bT where a and b are constants: a) Determine delta S for heating the gas from T1 to T2 at constant P b) Determine delta G for heating the gas from T1 to T2 at constant P HINT: the integral lnx dx= x ln x-x

Entropy change delta for argon gas

Find the entropy change delta for argon gas undergoing the following temperature and pressure changes: good Ar(g),P=1 atm, T=300 K------> Ar(g), P=10 atm, T=500K

Delta G

Consider the reacton: 2 H2(g) + O2(g) -------> 2 H2O(g). Determine delta G for this reaction at 1000 K.

Ions being reduced or oxidized

*** Please see file for full description*** 1. Into each of three potatoes insert 1 copper and 1 zinc probe. The probes should be inserted to a medium depth inside the potatoes and should be spaced within about an inch of each other. The probes should NOT touch inside or outside of the potato. IMPORTANT: To illuminate an

Assorted AP Chemistry Questions

Consider the reaction. Mn3N2 (s) +H2O (l) &#8594; Mg(OH)2 (s) + NH3 (g) a) Balance the equation and name each compound. b) How many moles of Mg(OH)2 are produced from .319 mol of magnesium nitride? c) How many grams of water are necessary to produce 4.39 mol of ammonia? d) If 12.48g of magnesium hydroxide are

Balancing a number of equations

Balance the following equations: a. S(2)O(3)^2- (aq)+I(3)^- (aq) ->S(4)O(6)^2- (aq) + I^- (aq) b. Mn^2+(aq) + HBiO(3) (s) ->MnO(4)^- (aq) + Bio^+ (aq) (acid) c. Cr(2)O(7)^2- (aq) + H(3)AsO(3) -> H(3)AsO(4) (aq) + Cr^3+ (aq) (acid) d. CIO^1(aq) + Cro(2)^- (aq) ->Cl^- (aq) + CrO(4)^2- (aq) (Basic) e. Obr^- (aq) +HPO(3)^2- (

AP Chemistry

Consider two solutions. One solution is 0.1115 M Ca(OH)(2). The other is 0.1050 M HClO(4). a) Write a balanced equation for the reaction between the two solutions. b) How many mL of Ca(OH)(2) will be required to neutralize 25.00 mL of the HClO(4)? c) If a student starts to titrate 31.39 mL of the Ca(OH)(2) solut

AP Chemistry

Question 3: The salt NaBrO(3) oxides Sn^2+ to SnCl(6)^2- in the presence of hydrochloric acid according to the equation 3 Sn^2+ (aq) + 18 Cl^- (aq)+ BrO(3)^- (aq) + 6 H^+ (aq) -> 3 SnCl(6)^2- (aq) + Br^- (aq) + 3 H(2)O A sample weighing 2.000g is