PASS MOCK EXAM – FOR PRACTICE ONLY
Course: __CHEM 1001 A/T___ Facilitator: _Saumya Bansal____
Dates and locations of mock exam take-up: Wednesday 4 – 5 30 (SA 502) Wednesday 6 30 – 8 (ME 3269) , Extra session maybe on Thursday (details in class)
IMPORTANT:
It is most beneficial to you to write this mock midterm UNDER EXAM CONDITIONS. This means:
1. • Complete the midterm in __1.5_ hour(s). 2. • Work on your own. 3. • Keep your notes and textbook closed. 4. • Attempt every question.
After the time limit, go back over your work with a different colour or on a separate piece of paper and try to do the questions you are unsure of. Record your ideas in the margins to remind yourself of what you were thinking when you take it up at PASS.
The purpose of this mock exam is to give you practice answering questions in a timed setting and to help you to gauge which aspects of the course content you know well and which are in need of further development and review. Use this mock exam as a learning tool in preparing for the actual exam.
Please note:
• Come to the PASS session with your mock exam complete. There, you can work with other students to review your work.
• Often, there is not enough time to review the entire exam in the PASS session. Decide which questions you most want to review – the facilitator may ask students to vote on which questions they want to discuss.
• Facilitators do not bring copies of the mock exam to the session. Please print out and complete the exam before you attend.
• Facilitators do not produce or distribute an answer key for mock exams. Facilitators help students to work together to compare and assess the answers they have. If you are not able to attend the PASS session, you can work alone or with others in the class.
DISCLAIMER: PASS handouts are designed as a study aid only for use in PASS workshops. Handouts may contain errors, intentional or otherwise. It is up to the student to verify the information contained within. PLEASE NOTE: THIS HANDOUT IS NOT TO BE POSTED ON THE INERNET
Required information:
ΔHNH3 = -45.9 kJ/mol
ΔHNO = 91.3 kJ/mol
ΔHH2O = -241.8 kJ/mol
ΔHHNO3 = -133.9 kJ/mol
R = 0.082 L atm K-1 mol -1
R = 8.314 L kPa K-1 mol -1
Part A. Answer each of the six questions with a few sentences or equations where necessary.
(5 Marks each)
1: In the van der Waals equation, why is the ‘a’ term for H2O larger than that for CO2?
2: Show the reactions in the catalytic cycle by which Cl atoms destroy ozone in the stratosphere.
3: Define what ‘Enthalpy of Formation of a compound’ means.
4: Name three ways that hydrogen might be stored in an automobile for use as a fuel.
5: Give two reasons why gases become less ideal at higher pressures.
6: What is the difference between a path function and state function? What kind of function is enthalpy? What kind of function is work?
Part B. Try to answer all 3 for the Mock. On the actual midterm only 2 out of the 3 will count.
B1. [6 marks] (a) At a particular temperature and pressure, it takes 4.55 minutes for a 1.5 L sample of He(g) to effuse through a porous membrane. How long will it take for 1.5 L of F2(g) to effuse under the same conditions?
(b) [6 marks] A sample of Freon-12 (CF2Cl2) occupies 24.5 L at 298 K and 253.3 kPa. Find its volume at STP.
(c) [8 marks] Chlorine is produced electrochemically from seawater and collected in a sealed container. If a 15.0 L container holds 0.580 kg of Cl2(g) at 200oC, calculate the pressure (in atm) using the van der Waals equation. For Cl2(g), a = 6.49 atm L2 mol-2 and b = 0.0562 L mol-1
B2. a) Ammonium Nitrate (NH4NO3, M =80.05g/mol) is used in cold packs to ice injuries. When 20.0 g of this compound dissolves in 125 g of water in a coffee-cup calorimeter, the temperature falls from 23.5 ⁰ C to 13.4 ⁰ C. Determine q for the dissolving compound.
b) For the following reaction calculate the energy change per mole of HNO3 formed.
12 NH3 (g) + 21 O2 (g) -( 8 HNO3 (g) + 4 NO + 4 H2O (g)
c) An aluminium frying pan that weighs 745 g is heated on a stove from 25 ⁰ C to 205⁰ C. What is q for the frying pan? (CAl = 24.35 J mol -1 ⁰C -1)
B3.a) When launching a space shuttle, a high pressure pump brings 4,400kg of liquid H2 and 31,000kg of liquid O2 to each of the main engines each minute. At 1 atm and 300K, what volume of water vapour (H2O(g)) is produced from the reaction between hydrogen and oxygen each minute from the engine?
b) Calculate for the reaction 2 Al (s) + 3 Cl2 (g) -( 2 AlCl3 (s) from the data.
|2 Al (s) + 6 HCl (aq) -(2 AlCl3 (aq) + 3 H2 (g) |ΔH = -1049. kJ |
|HCl (g) -(HCl (aq) |ΔH = -74.8 kJ |
|H2 (g) + Cl2 (g) -(2 HCl (g) |ΔH = -1845. kJ |
|AlCl3 (s) -( AlCl3 (aq) |ΔH = -323. kJ | 