Physical Chemistry Answers

What is the limiting reactant

Make a creative story about the lesson of the polarity of molecules

Vinegar and water are placed in a 1000ml bottle. Determine the mass of each of the substances placed inside the bottle if the product is a 75% water solution.( density of vinegar= 960 kg/cu m, density of water=1000 kg/cu m.​

5.0 mole of ammonia were introduced into a 5.0 L reaction chamber in which it is partially decomposed at high temperature. At equilibrium at a particular temperature,80% of the ammonia had reacted. calculate Kc?

State six reasons why measurements are done in chemistry and how a measure is stated

2. 10.0 g of steam at 120.0 °C are converted into ice at -20.0°C.

a) Make a graph to indicate this change.

b) Calculate the total energy released (J) needed to do the problem above.

1. A sample of water with a mass of 23.0 grams at a temperature of -46.0°C increases to 40°C.

a) Make a phase change diagram to indicate the changes water will undergo in this problem & label each step.

b) How much total heat (Joules) is needed to do the problem above?

1. A sample of gaseous uranium hexafluoride, UF6, is held at a temperature of 300 K and a pressure of 0.1 mbar. The collision diameter of UF6 is 0.40 nm. (i) Calculate the root-mean-square (r.m.s.) speed of the molecules. Make sure to show all units in your working and how the units cancel out. [5 marks] (ii) Estimate the mean free path and collision frequency under these conditions. [10 marks]

Suppose that you are travelling in the Space Shuttle Endeavor on a journey to Mars. The atmosphere (of the vehicle) consists of 20% oxygen and 80% helium by volume. It was noticed before take off from the Kennedy Space Center that there is a small leakage which if unchecked, would lead to a continual loss of gas at a rate of 0.05 atm/day through effusion. If the temperature in the space shuttle is maintained at 22°C and the volume of the vehicle is 15,000 liters. Calculate the amounts of helium and oxygen in grams that must be stored on a 5-day journey to allow for the leakage.

1. Predict  How would the data in the diagram change if the pressure was 3 atm instead of 1 atm?