c205_final_w04_04_hints

c205_final_w04_04_hints - Course CHEMISTRY Instructor P.H...

Info icon This preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Course: CHEMISTRY Number: 205/4 Section: 04 Instructor: P.H. Bird Examination: Alternate Date: 25th April, 2004 Time: 9:30-12:30 am # of pages: 14 Materials Allowed: A periodic table is attached to this paper - no other materials are allowed . Calculators Allowed: Yes Special Instructions: Please answer 25 questions. The first 20 are multiple choice and carry 5 marks each. The others require complete answers and are worth 10 marks each. Please read the instructions before each group of questions . Name: __________________________________ Student Number:______________ 1 2 3 4 5 6 7 8
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Chem 205 Winter 2004 Final Exam Section 04 page 2 The following 20 questions are multiple choice. You may do rough work on your exam paper, but you must mark you answers using a soft pencil on the machine readable answer form provided. Do not forget to mark your name and student number . 1. Magnesium makes up 1.3 x 10 -4 percent by mass of the elements found in a normal healthy human body. How many grams of magnesium would be found in the body of a person weighing 183 lb? (2.2 lb = 1 kg) a. 1100. g b. 0.11 g c. 11. g d. 0.24 g e. 0.10834 g Hint: You need to know the definition of percent by mass. 2. The element rhenium (Re) exists as two stable isotopes and 18 unstable ones. Which of the following represents the contents of the nucleus of 185 Re? a. 75 protons, 75 neutrons b. 75 protons, 130 neutrons c. 130 protons, 75 neutrons d. 75 protons, 110 neutrons e. 75 protons, 110 electrons Hint: You need to know how the atomic symbols are written, and specifically what that left superscript represents. 3. How many oxygen atoms are there in one formula unit of the type of of asbestos called chrysotile, Mg 3 Si 2 O 5 (OH) 4 , which is mined around Thetford Mines in Quebec? Hint: You need to know how to “read” a chemical formula.
Image of page 2
Chem 205 Winter 2004 Final Exam Section 04 page 3 4. Find the error in the following pairs: a. NH 4 Br, ammonium bromide b. K 2 CO 3 , potassium carbonate c. BaPO 4 , barium phosphate d. CuCl, copper(I) chloride e. MnO 2 , manganese(IV) oxide Hint: If you assign the correct charges to each of the ions in them, one of the compounds would not have a zero total charge: which one? Of course, you need to recognize the ions. 5. Iron is biologically important for the transport of oxygen by red blood cells from the lung to various parts of the body. In the blood of an average human being, there are approximately 2.60 x 10 13 blood cells with a total of 2.90 g of iron. How many iron atoms are there in the average blood cell? (N a = 6.022 x 10 23 ) Hint: Avagadro’s number, N a , is given. You need to know what it is o answer this question.
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern