Summer Holidays Questions

Transcription

1 Summer Holidays Questions Chapter 1 1) Barium hydroxide reacts with hydrochloric acid. The initial concentration of the 1 st solution its 0.1M and the volume is 100ml. The initial concentration of the 2 nd solution is 0.1M and 50ml. Write the balanced chemical equation including states, find the limiting reactant and calculate the %atom economy. 2) By using the ideal gas equation calculate the mass of hydrogen and nitrogen gas systems in a container of 100ml for each of the substances, under standard conditions. Which of the two has higher mass and why? 3) A student has created a stock solution of 1M of HCl acid. The student wants to dilute this solution using a 100ml graduated cylinder to the concentration of 0.01M. Calculate how much water should be added to this solution.

2 Chapter 2 4) Write the electron shell configuration of Fe and the corresponding configurations of its ions. Also use the electron in a box method to write how the valence electrons are distributed in the valence orbitals. 5) Draw the pattern of the successive ionization energies of Mg. Explain the trend observed. Also draw the mass spectrum of Mg by labeling the axes.

3 Chapter 3 6) Write the chemical reactions between K and water, Na and water, potassium oxide with water and sodium oxide with water. Explain any observations during the chemical reactions and state which of the 1 st and 3 rd reactions will be more vigorous. 7) Write and explain which reaction will take place: potassium chloride with bromine or potassium bromine with chlorine? State any observations that might take place during the feasible reaction. 8) From ex.56 pg. 134 from your book, draw the absorption spectrum of the complexes provided. Which are the colors of these complexes?

4 Chapter 4 9) Find the hybridization of C and oxygen in carbon monoxide and carbon dioxide. Draw the orbitals that participate to the formation of π bonds in both cases. 10) Draw the Lewis structure of ethanoic acid and its conjugate base. Explain the type of bonding between the C atom and the oxygen atoms. How much is the angle between oxygen-carbon-carbon in ethanoic acid? 11) Draw the Lewis structure of carbonate ion and state the molecular and electron geometry of the ion.

5 Chapter 5 12) Calculate the formal charge of nitrogen monoxide and nitrogen dioxide. (ch4) Write the combustion reactions that lead to the formation of these compounds. 13) Calculate the enthalpy change of nitrogen monoxide reacting with oxygen in order to produce nitrogen dioxide. Write the states for reactants and products and calculate the enthalpy change with 3 different ways. 14) Use an energy cycle in order to calculate the enthalpy of solution of potassium bromide.

6 Chapter 6 15) Can you calculate the activation energy of the reaction found on pg. 287 of your text book? Why? Which is the order of that reaction? Are you in position to calculate the half life of this reaction? 16) Using the previous exercise plot the graph of the rate constant k as a function of 1/temperature from temperatures ranging from 296 (23 o C) to 316 K with increments of 10K. Use the value of 90kJ/mol for the activation energy of the decomposition reaction.

7 Chapter 7 17) For the Haber process calculate the standard Gibbs free energy change. Then calculate the equilibrium constant. Find the standard change in entropy under standard conditions and comment on the sign of ΔS. 18) Find the equilibrium concentrations of exercise 17 if the initial concentrations of hydrogen and nitrogen are 0.1M and K c = 1.6x10-4.

8 Chapter 8 19) Calculate the ph of a 0.1M barium hydroxide solution, ammonia and potassium hydroxide. How much the ph will change in all cases if their initial concentrations are reduced to one half of their original values? 20) From the K a value of acetic acid calculate the pk a value. Then find the ph of a 6 degrees vinegar solution. Then create a new diluted 100ml solution with ph=3. For this new solution calculate how much water should be added to the original vinegar solution. Propose a way in order to create a 100ml, ph=5 vinegar solution.

9 Chapter 11 21) From pg. 546 calculate the R values for all 3 different cases. 22) Thomas was measuring the change of pressure over change of time for a chemical reaction using digital instruments. The temperature recorded was room temperature. The data collection was the following: Trial 1 Trial 2 Trial 3 Time kpa kpa kpa 0.0 s kpa kpa kpa 4.0 s kpa kpa kpa 8.0s Calculate, with the correct number of significant figures and units, the average rate of the chemical reaction and the corresponding uncertainty during the time range of 8.0 seconds. If the volume of the container was ml, calculate, with the correct number of significant figures and units, the rate of reaction as the change of concentration over change of time.