Physical Chemistry Answers

For 2AB+C₂ → A₂+2BC, suppose AH = 100kJ, E₁-250kJ, and that the intermediate is A + C. Describe a potential energy process for this reaction. You do not need to use your reaction mechanism for this question.

A 10kg block of aluminum (p=2700 kg/ m^3) is attached to a rope. Find the tension force in the rope if the block is in vacuum? What is the tension force in the rope if the block is in air (p=1.29 kg/m^3) and What is the tension force if the block is in water?

Suppose we have 2.0 g of ethyl alcohol at -50 degree celsius and we remove heat to it continuously. let us also assume that no heat is lost to the surroundings. How much heat is to be removed to convert this from liquid to solid at -120 degree celsius.

How would you prepare 500ml of 28% w/v (weight/volume) KOH (potassium hydroxide) solution? From this stock, how would you prepare a 0.1M working solution?

1) The first law of thermodynamics is a version of the law of conservation of energy. What does this mean in terms of the exchange of heat and work in a closed system?

1.    The volume sample of gas is 750 mL at 60°C and 0.7 atm. At what temperature will the sample 1.75 L occupy under a pressure of 1.80 atm?

Determine if the entropy change will be positive or negative for the following reactions:

H2 + N2 → NH3

When aqueous solutions of Na₂SO₄ and Pb(NO₃)₂ are mixed, PbSO₄ precipitates. Calculate the limiting reagent and mass of PbSO₄ when a 1.25 L solution of 0.0500 M Pb(NO₃)₂ and a 2.00 L solution of 0.0250 M Na₂SO₄ are mixed. (Hint: start first by balancing the equation of the reaction between Na₂SO₄ and Pb(NO₃)_2.

When aqueous solutions of Na₂SO₄ and Pb(NO₃)₂ are mixed, PbSO₄ precipitates. Calculate the limiting reagent and mass of PbSO₄ when a 1.25 L solution of 0.0500 M Pb(NO₃)₂ and a 2.00 L solution of 0.0250 M Na₂SO₄ are mixed. (Hint: start first by balancing the equation of the reaction between Na₂SO₄ and Pb(NO₃)_2.

What happened to the number of moles in a sample that originally occupied 500 mL with 2.50 moles and then occupied 750 mL?