Physical Chemistry Answers

For a saturated solution of AgCl at 25°C,the specific conductance was found to be 3.41×10^-6 ohm^-1 Cm^-1. The specific conductance of water the water used to make up the solution was 1.6×10^-6 ohm^-1 cm^-1. Determine the solubility of AgCl in water in moles per litre at 25°C, given that the equivalent conductance of AgCl at infinite dilution at this temperature is 138.3 ohm^-1 cm^-1 equiv.^-1

The equivalent conductance of sodium acetate,hydrochloric acid and sodium chloride at infinite dilution is 97.0, 426.16 and 126.45 ohms^-1 respectively at 25°C .calculate the equivalent conductance at infinite dilution for acetic acid

Dilution Practice
1. How many liters of 4.3 M Li2O solution are required to make 5 L of 2.1 M Li2O solution?


2. How many milliliters of a 6.0 M HCl solution are required to make 2.0 L of 2.7 M HCl?


3. How could you prepare 300 mL of 0.45 M LiBr using a solution of 1.7 M LiBr and water?


4. How could you prepare 10 L of 0.1 M NaOH using 1.0 M NaOH and water?


5. What is the molarity of a solution made by diluting 1.2 L of 7 M KCl with 0.8 L of water?

Molarity Practice
1. Calculate the molarity of a solution in which 0.50 moles of MgCl2 are dissolved to produce 1.5 liters of solution.


2. Calculate the molarity of 1 mole of NaNO3 in 500 mL of water.


3. How many grams of LiOH are required to make 4.2 L of a 0.98 M solution?


4. What volume of 0.25 M solution can be prepared using 0.50 moles of KCl?


5. Calculate the molarity of a 250 mL solution containing 85.0 g of BaCl2.




6. What volume of 0.10 M solution can be prepared using 11.6 g of NaCl?


7. How many moles of CaO are required to make 48 mL of 0.1 M solution?


8. How many grams of Ca(OH)2 would be required to make 500 mL of a 2.5 M solution?

Henry’s Law Practice
1. The solubility of a gas is 0.58 g/L at a pressure of 104 kPa. What is the solubility if the pressure increases to 250 kPa at constant temperature?


2. The solubility of a gas is 1.6 g/L at 760 mmHg. What is the solubility of the same gas at a pressure of 2.5 atm? Assume temperature to be constant.


3. A gas has a solubility of 2.45 g/L at a pressure of 0.750 atm. What pressure would be required to produce an aqueous solution containing 6.25 g/L of this gas at constant temperature?

0.14941 wt% aqueous KCl solution
at 25°c was electrolyzed in a hittorf apparatus using two Ag-AgCl electrods .The cathode reaction was AgCl+ e ~ Ag + Cl- , the anode reaction was the reverse of this .After the experiment ,it was found that 143.34 C charge had been flown through the apparatus and that the cathode compartment contained 120.99g of solution
that was 0.19404wt% KCl by weight.Calculate t+ and t- in the KCl solution
used in the experiment ,neglect the transport of water by ions.

What is more effective to improve efficiency of carnot engine to increase source
temperature keeping sink temperature constant or to decrease sink temperature keeping
source temperature constant.

A 30.0 mL sample of 0.200 mol/L hydrobromic acid solution (HBr(aq)) was titrated with a 0.200 mol/L potassium hydroxide solution (KOH(aq)). Which one of the following statements concerning the pH curve of this reaction would be incorrect?
A. There would be one sharp change in pH during the titration.
B. The pH of the solution would increase as the titration progressed.
C. Methyl orange could be used to detect the point at which the reaction was complete.
D. The pH of the hydrobromic acid solution would change slowly at the beginning of the titration.

2. You spill some sugar in a sandbox. You scoop it up as best you can, but now you have a mixture of sand and sugar. How could you separate the two?

For the half cell reaction
NO2 +2OH ----NO3 +H2O +2e-
E°cell is +0.425.if the overall potential is 0.6250.what is the pH of the solution at:(1) 25°C (2)47°C.if the concentrations of the nitrite ion and nitrate ions are 0.10 and 1.97×10^-10 mol/dm^3 respectively.