CHE 1301 Exam 3 Test Review PDF

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CHE 1301 – HODSON Exam 3 Test Review

Supplemental Instruction 11-08-2017 Exam 3 Test Review

Part 1: Determine if the following statements are true or false. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22.

23. 24. 25.

Redox reactions involve hypothetical charges not real charges. Dissociation is the same thing a solvation. The analyte in a titration become neutral. Stoichiometric coefficients in a reaction indicate a molar relationship. A strong acid or strong base are non-electrolytes. Oxidation numbers indicate that covalently-bonded elements have charges. A molecular formula is the simplest formula for a compound. The atomic mass of an atom is the weighted average of all the naturally occurring isotopes. Molarity is defined as the moles of solute per mL of solvent. After a reaction has gone to completion, it results in an ionic compound precipitate. This ionic compound precipitate is a strong electrolyte. 6 M HF is a stronger acid than 2 M HCl since it has a higher molarity. An oxidizing agent is reduced during a redox reaction. The limiting reagent is always the reagent that has the smallest amount of mass. Reduction ALWAYS occurs alone. A mole is an amount of any substance that contains as many elementary particles as there are atoms in exactly 12 g of carbon-12. The atomic mass in u is the same as the atomic mass in g. An empirical formula is deduced from an experimentally determined percent composition. We can interpret balanced equations on a molar basis, which allows for it to be determined on a mass basis. When substances react independently and at the same time, it is called a simultaneous reaction. An Arrhenius acid is one that produces hydrogen ions in water. At the equivalence point, the acid and base have been brought together in exact stoichiometric coefficients. In oxidation-reduction reactions there is a net movement of electrons from one reactant to another, with the movement of electrons occurring in the formation of both ionic and covalent compounds. The oxidation number of an element that is being reduced decreases. Electrons are on the product side for an oxidation half-reaction. A disproportionation reaction involves the same species being both oxidized and reduced.

Part 2: Chapter Reviews: 1. Determine the number of atoms in 34.4 g of Magnesium.

2. Find the mass of phosphorous that contains the same number of atoms as 70.8 g of Mg does.

CHE 1301 – HODSON Exam 3 Test Review

Supplemental Instruction 11-08-2017

3. Calculate the molar mass of C6H12O6.

4. Find the mass in amu of 4 moles of CH3.

5. Find the mass percent of carbon in glucose (C6H12O6).

6. 1.893 g of estrone, which contains only carbon, hydrogen, and oxygen goes through combustion analysis. It produces 5.545 g CO2 and 1.388 g H20. The molar mass of estrone is 270.36 g/mol Find the molecular formula.

7. Balance the following reactions: a) ____CO2(g) + ____CaSiO3(s) + ____H20 (l)  _____SiO2(s)+ _____Ca(HCO3)2(aq)

CHE 1301 – HODSON Exam 3 Test Review

Supplemental Instruction 11-08-2017

b) ____ C5H10(s) + ____O2(g)  ____ CO2(g) + ____ H20(l)

8. Balance the following reaction: ______C6H14 + ____O2  ______CO2 + _______H2O

a) How many moles of O2 are needed to react completely with 7.2 moles of C6H14? How many grams?

b) How many moles of C6H14 is needed to produce 53 kg of water?

CHE 1301 – HODSON Exam 3 Test Review

Supplemental Instruction 11-08-2017

9. Iron (II) sulfide reacts with hydrochloric acid. Write out this reaction and balance it.

A reaction mixture initially contains 0.223 moles FeS and possibly 0.652 moles HCl. Once the reaction has occurred as completely as possible, what amount (in moles) of the excess reactant is left?

10. Lead ions can be precipitated from the solution KCl according to the reaction: Pb2+aq) + 2KCl (aq)  PbCl2(s) +2K+(aq) When 25.8 g KCl is added to a solution containing 25.7 g lead ions, the solid precipitate forms. The precipitate is filtered and found to have a mass of 29.4 g. Determine the limiting reactant, theoretical yield, and percent yield of the reaction.

11. Utilize the reaction from number 2. If the percentage yield of the reaction is 30.5 % in lab, how many grams of Iron (II) Sulfide is needed to produce 50.7 grams of product.

CHE 1301 – HODSON Exam 3 Test Review

Supplemental Instruction 11-08-2017

12. Calculate the molarity: 3.25 g LiCl in 2.78 L solution.

13. Calculate the moles of Ca(NO3)2 in 0.556 L of 2.3 M Ca(NO3)2. Also, how many moles of nitrate ions are there?

14. What volume of 2 M Sodium Sulfate stock solution is needed to prepare 0.547 L of 0.500 M Sodium Sulfate?

15. Circle which of the following are acids and box which of the following are bases:  HF  LiOH  NH3  CH3NH2  HI  NH3  HNO3  RCOOH  HRCO2 16. You perform an acid-base titration to standardize an HCl solution by placing 50.00 mL of HCl in a flask with a few drops of indicator solution. You put 0.200 M NaOH into the buret, and the initial reading is 50.53 mL. At the endpoint, the buret reading is 40.99 mL. What is the concentration of the HCl solution?

CHE 1301 – HODSON Exam 3 Test Review

17. a) b) c) d) e) 18. a)

Supplemental Instruction 11-08-2017

Assign oxidation numbers to each element in the following. Ag+ CuCl2 Cr2O72Cl2 CH4 Figure out if each of the following reactions is redox or not. Ba(s) + Cl2(g)  BaCl2 (s)

b) Mg(s) + Br2(l)  MgBr2(s)

19. Find the products and balance each reaction. Write the net ionic equation and the ionic equation if applicable. Does a reaction occur? 1) Potassium Chloride + Calcium Sulfide 

2) Calcium Bromide + Sodium Carbonate 

CHE 1301 – HODSON Exam 3 Test Review

3) Hydrobromic Acid + Potassium Hydroxide 

Supplemental Instruction 11-08-2017...