CHEM 1A03 Study Guide - Final Guide: Unpaired Electron, Electron Configuration, Sodium Chloride
Name: ________________________ Student Number: _______________
continued on next page ... Version 1 Page 1
CHEMISTRY 1E03 13 DECEMBER 2010
McMASTER UNIVERSITY - FINAL EXMINATION - answers
DURATION: 3 HOURS
Instructor: J. Barbier
This examination paper contains 21 pages and 35 multiple-choice questions.The last pages
include extra blank pages for rough work, a page with some useful data and equations, and a
Periodic Table. You may tear off the last five pages. You are responsible for ensuring that your
copy of the question paper is complete. Bring any discrepancy to the attention of your invigilator.
Questions 1-25 are each worth 2 marks, questions 26-35 are each worth 3 marks. There is no
penalty for incorrect answers. Answer all questions on the answer sheet, in pencil. Instructions
for entering multiple-choice answers are given on page 2. Select one answer only for each
question.
These question sheets must be returned with your answer sheet. However, no work written on
the question sheets will be marked. You must enter your full name and student number on this
question sheet, as well as on the answer sheet. Your invigilator will be checking your student
card for identification.
Make sure to enter the correct version number of your examination (shown at the bottom of
each page) in the correct column on the answer sheet (see instructions on page 2).
Only Casio FX 991 electronic calculators may be used; but they must NOT be transferred between
students. Use of periodic tables or any aids other than those provided, is not allowed.
Note: Academic dishonesty may include, among other actions, communication of any kind (verbal, visual, etc.) between
students, sharing of materials between students, copying or looking at other students’ work. If a problem arises, please
ask an invigilator to deal with it for you.
Name: ________________________ Student Number: _______________
continued on next page ... Version 1 Page 2
QUESTIONS 1–25 ARE WORTH 2 MARKS EACH.
1. The electrolysis of NaCl(aq) yields chlorine gas and hydrogen gas as per the unbalanced
reaction below:
Cl– (aq) + H2O(l) OH–(aq) + H2(g) + Cl2(g).
Balance the reaction and identify the false statement below.
A) The electrolysis of 1 mole of sodium chloride produces 2 moles of hydrogen gas.
B) The oxidation state of oxygen remains unchanged.
C) A total of 2 moles of electrons are transferred during the production of 1 mole of
chlorine gas.
D) Water acts as an oxidizing agent in the reaction.
E) The pH of the NaCl(aq) solution changes from neutral to basic during electrolysis.
2. As 20.0 g of solid NH4NO3 is dissolved in 100.0 cm3 of pure water, the temperature of the
solution changes from 22.3°C to 7.0°C. Calculate the enthalpy of dissolution of NH4NO3
(in kJ mol–1). Assume that the specific heat of the solution is equal to that of pure water
(4.184 J·g–1·K–1).
A) +25.6
B) +30.7
C) +20.4
D) -30.7
E) -25.6
3. Which atom has the largest number of unpaired electrons in its ground-state electron
configuration?
A) S
B) Be
C) Mn
D) Ni
E) N
Name: ________________________ Student Number: _______________
continued on next page ... Version 1 Page 3
4. Identify the false statement(s):
(i) The energy of a closed system cannot change.
(ii) White P and red P are two allotropes of phosphorus. Given that white P is the standard
form, the red P
white P conversion is an endothermic process under standard conditions.
(iii) For a chemical system to do mechanical work, its volume must increase.
(iv) The equation w + q = 0 expresses the first law of thermodynamics applied to an
isolated system undergoing some transformation.
A) iii, iv
B) ii, iv
C) i, ii
D) i, iii
E) iii
5. For the reaction of 15.0 g of magnesium and 5.00 g of nitrogen according to:
3 Mg + N2 Mg3N2, which statement is true?
A) There is an excess of 0.082 mol of Mg .
B) 15.0 g of Mg3N2 is produced.
C) There is no limiting reagent.
D) 20.0 g of Mg3N2 is produced.
E) There is an excess of 0.44 mol of N2 .
6. 500-nm light is used to eject electrons from cesium metal. Which one of the following
three statements is false?
A) Electrons will also be ejected by 450-nm light and they will have a greater kinetic
energy.
B) The kinetic energy of each ejected electron is greater than 3.97 × 1019 J.
C) 500 nm light is part of the visible electromagnetic spectrum.
35
CHEM 1A03 Full Course Notes
Verified Note
35 documents
Document Summary
This examination paper contains 21 pages and 35 multiple-choice questions. The last pages include extra blank pages for rough work, a page with some useful data and equations, and a. You may tear off the last five pages. You are responsible for ensuring that your copy of the question paper is complete. Bring any discrepancy to the attention of your invigilator. Questions 1-25 are each worth 2 marks, questions 26-35 are each worth 3 marks. Answer all questions on the answer sheet, in pencil. Instructions for entering multiple-choice answers are given on page 2. These question sheets must be returned with your answer sheet. However, no work written on the question sheets will be marked. You must enter your full name and student number on this question sheet, as well as on the answer sheet. Your invigilator will be checking your student card for identification.
