Basic Laboratory Skills Model Exam Paper

Intake: January 2014 Page 1

1/14 CONFIDENTIAL Semester1 Model Examination Paper

Name: _________________________________

Matric No: _____________________________

MAHSA UNIVERSITY

FOUNDATION IN SCIENCE

Semester 1 Model Examination Paper

Batch: January 2014 (1/14)

BASIC LABORATORY SKILLS

SUBJECT CODE : FSC BLS 112 DATE : TIME : (2 Hours)

EXAMINATION ATTENDANCE SLIP

NAME : _____________________________

MATRIC NUMBER : _____________________________

SEMESTER : _____________________________

SUBJECT : _____________________________

COURSE CODE : _____________________________

VENUE : _____________________________

DATE : _____________________________

SIGNATURE OF CANDIDATE :_____________________________

INSTRUCTIONS

This examination paper consists of Section A, B, C and D. Answer ALL questions.

Questions appear from printed pages 3 to 16.

DO NOT OPEN THE BOOKLET UNLESS INSTRUCTED tear here


SECTION A

20 Objective

Question

/20

SECTION B

Biology Structure

Questions

/20

SECTION C

Chemistry

Structure

Questions

/20

SECTION D

Physics Structure

Questions

/20

TOTAL

Total

/80

Scaled-down

(60%)

/60


SECTION A: MULTIPLE CHOICE QUESTIONS.

[20 marks]

Instruction: Answer ALL questions. Shade your answer in the OMR

sheet provided.

1. Identify above symbol.

A. Toxic

B. Poisonous

C. Corrosive

D. Compressed Gas


A. Flammable

B. Poisonous

C. Toxic

D. Corrosive


A. Dangerous Reactive

B. Oxidizing

C. Flammable

D. Toxic


4. Identify the Biohazard Waste symbols.

A.

B.

C.

D.

5. What is important to remember while you using heat?

A. Do not heat close container

B. Point the mouth of the container away from yourself and classmate.

C. Always use clamp to hold container

D. All of the above.

6. Which of the following is NOT TRUE?

A. Add acid to water

B. Pipette by mouth

C. Keep flammables away from open flames

D. Never use chipped glasses.

7. Long and loose hair is a problem because

A. It might contaminate your experiments.

B. It makes it harder to wear safety goggles.

C. If you turn too quickly, your hair might knock a jar of chemicals off.

D. Hair burns very quickly.


8. What would immediately be used if your clothing caught or if a large chemical Spill

had occurred on your clothing?

A. Fire Extinguisher

B. Safety shower

C. Laboratory sink

D. Eye-Wash fountain

9. After completing an Experiment, all materials waste should be:

A. Dumped into the sink

B. Left it on your table for next class

C. Disposed according to your lecturer instructions

D. Take home.

10. You have been injured in the lab (burn, cut, etc). You Should:

A. Inform your Lecturer or Lab Assistant

B. See the doctor after class

C. Apply first aid by yourself

D. Tell your close friends

11. What thing you need to wear before beginning your practical in the laboratory?

A. Safety apron or a lab coat

B. Glove

C. Goggles

D. All of the above

12. What should do you do if a glass breakage Occur?

A. Immediately contact your lecturer or Lab Technician.

B. Leave where it is without telling anyone

C. Run out of the laboratory

D. Touch it and see if it safe

13. What should you maintain in your work lab area?

A. Clean and tidy work space

B. Chemical spill around you

C. Messy work space

D. Lots of food and drink

14. What should you do if a flame from a burner leaps out of burner toward you?

A. Get out of the way and turn the gas immediately

B. Touch the flame to see how hot it is

C. Touch it with your finger to turn off the fire

D. None of these

15. If you are heating a container, what you should NEVER do?

A. Test its temperature

B. Pick up the container with your hand

C. Pick up the container with a clamp

D. All of these


16. What should you NEVER do in the laboratory?

A. Play practical joke on people

B. Run while holding a beaker with chemical

C. Mess around with your friend.

D. All of these.

17. When you complete your work in the laboratory, which of the following should

you NOT do?

A. Clean and return materials to the lab cart

B. Try your own experiment

C. Submit your experiment report

D. Return to your own seat

18. When you find an unlabeled bottle of chemical in the lab, you should:

A. Smell it and see what it is

B. Ask your lecturer

C. Waft the chemical

D. Pour it down the drain

19. Laboratory clothing from a safety point of view should follow these guidelines

below EXCEPT for

A. Finger rings or other tight jewelry which is not easily removed should be

avoided.

B. Where infectious materials are present, lab coats and gloves are essential.

C. Sandals, open-toed shoes, and shoes with woven uppers, can be worn.

D. Find out the recommended clothing to wear for a particular chemical.

20. Which of the following statement is TRUE?

A. Dazzling, dangling jewelry is OK in the lab, as long as care is taken

B. Earphones are acceptable, provided you are careful when doing a lab

C. Put your contact lenses in your eyes, as soon as you enter the lab

D. Contact lenses should not be worn, especially when working with chemicals

---------------------------------------END OF SECTION A -----------------------------------


SECTION B: BIOLOGY

STRUCTURE QUESTIONS

[20 marks]

Instruction: Answer ALL questions in the space provided in this question

paper only. Label clearly all drawings and diagrams. Answer to

calculations must be shown with the appropriate significant figure and

decimal place, with the correct units, if any. Write all your answers in

PEN. The use of pencil is only limited to sketching and drawing.

QUESTION 1

(a) (i) What is the function of the stage knob?

………………………………………………………………..

………………………………………………………………..

[1 mark]

(ii) When observing a specimen at 1000x magnification, which

focusing knob are you going to use and explain the reason for

using this knob?

………………………………………………………………..

………………………………………………………………..

[2 marks]

(iii) What do you understand by the term ‘depth of view’?

…………………………………………………………………

[1 mark]

(iv) Explain the steps involved in observing a specimen under a

microscope.

…………………………………………………………………

…………………………………………………………………

…………………………………………………………………

[2 marks]

(b) (i) What is a wet mount?

……………………………………………………………….

……………………………………………………………….

[2 marks]


(ii) A drop of iodine solution was added to the wet mount. What

is the purpose of adding iodine?

……………………………………………………………….

……………………………………………………………….

……………………………………………………………….

……………………………………………………………….

……………………………………………………………….

……………………………………………………………….

……………………………………………………………….

……………………………………………………………….

[4 marks]

(iii) How to avoid getting fingerprints on the coverslip?

……………………………………………………………….

……………………………………………………………….

[1 mark]

(c) A nutritional drink contains reducing sugar and protein. Describe how you

would test this drink for the presence of reducing sugar and protein. Include a

description of the test results you would expect.

(i) Reducing sugar.

……………………………………………………………….

……………………………………………………………….

……………………………………………………………….

……………………………………………………………….

……………………………………………………………….

……………………………………………………………….

……………………………………………………………….

[4 marks]

(ii) Protein.

……………………………………………………………….

……………………………………………………………….

……………………………………………………………….

……………………………………………………………….

[3 marks]

---------------------------------------END OF SECTION B -----------------------------------


SECTION C: CHEMISTRY

STRUCTURE QUESTIONS

[20 marks]






Question 1

Read the Scientific Laboratory Report below carefully. Construct an Abstract based on

this report. Your Abstract should be between 90 – 150 words and be written in one

paragraph.

[10 Marks]


Synthesis of Ethyl ethanoate Derived from Ethanol and

Ethanoic Acid

Prepared by: Lehman, Baty

Date: 14 February 2014

INTRODUCTION

The general formula of esters is CnH2n+1COOCmH2m+1 where n = 0, 1, 2, 3 ... and m =

1, 2, 3 ... The values of m and n in both the alkyl groups may be the same or different.

Esters are formed by the reaction between carboxylic acid and alcohols. Hence the

general formula of esters is obtained by combining the general formulae of carboxylic

acid and alcohol [1]. The general formula of an ester is derived as follows.

Figure 1:

General formula of an ester

The general formula of esters can also be represented as RCOOR’, where R and R’

represent the same of different alkyl group. Esters have general characterizations and

this can be used to distinguish the difference between ester and the reactants (alcohol

and carboxylic acid). The obvious physical characteristics of an ester are colourless,

fragrant smell, insoluble in water and low density in water [2].

Hence, the objectives of this experiment are to synthesis ethyl ethanoate from ethanol

and ethanoic acid, and to determine the characteristic of the ester by observe the

colour, smell and solubility test.

MATERIALS AND METHOD

Apparatus

1. Round bottom flask

2. Liebig condenser

3. Tile chips

4. Retort stand with clamp

5. Oil bath


Materials

1. Pure ethanol

2. Glacial ethanoic acid

3. Concentrated hydrochloric acid

Methodology

Synthesis of ethyl ethanoate

30 cm3 of pure ethanol was placed in a round bottom flask, followed by 25 cm

3 of

glacial ethanoic acid and 2 pieces of tile chips. 5 cm3 of concentrated sulphuric acid

was added cautiously to the mixture. The mixture was shaken gently was boiled under

reflux for 30 minutes (Figure 2). The pure ethyl ethanoate was obtained by distillation

[3].

Figure 2:

Reflux set up for esterification process

Confirmation Test

The confirmation tests were done by observing the physical state of ethyl ethanoate

and solubility test [3].

RESULT

Table 1:

Confirmation test for Ethyl ethanoate

Confirmation Test Result or observation

Colourless

Fragrant smell

Solubility in water Insoluble in water

Density in water Low density

Oil bath


DISCUSSION

When ethanoic acid and ethanol were heated in the presence of concentrated sulphuric

acid, ethyl ethanoate was produced (Figure 3). In this reaction, ethyl ethanoate act as a

catalyst to speed up the reaction and absorb moisture.

Based the result tabulate in Table 1, ethyl ethanoate produced shows physical

properties that match with the general physical properties of ester which are

colourless, fragrant smell, insoluble in water and low density in water.

Figure 3

Reaction between ethanoic acid and ethanol

CONCLUSION

Ethyl ethanoate was successfully synthesized from ethanoic acid and ethanol with the

presence of concentrated sulphuric acid as a catalyst. Confirmation tests were done

and the result shows the product produced have physical characters that match with the

general physical characters of an ester.

REFERENCES

[1] J. McMurry, Organic Chemistry, Sixth Edition ed., United State of America:

Thomson, 2004.

[2] R. Chang, Chemistry, Ninth ed., United States of America: McGraw Hill

International Edition, 2007.

[3] K. Kassim, Organic Practice, Malaysia: UPENA, 2010

H3CC

O

OH H3C C

H

OH

H

H3C C

H

O

H

C

O

CH3

conc. H2SO4


ABSTRACT


Question 2

a)

Figure above shows 25 cm3 of hydrochloric acid in a conical flask. Between

measuring cylinder, burette and pipette, which one is the most suitable apparatus

that can be used to measure this 25 cm3 of hydrochloric acid? Explain your

answer.

[2 Marks]

b. Table below shows the results of an initial and a final reading of a burette for

Acid Base Titration. Calculate the volume used and the average volume used.

[2 Marks]

Rough 1st Titration 2

nd Titration 3

rd Titration

Initial

Reading (cm3)

3.30 5.80 0.80 1.70

Final Reading

(cm3)

27.10 30.30 25.30 27.30

Volume used

(cm3)

Average

volume used

(cm3)

c. Can I titrate a solution of unknown concentration with another solution of

unknown concentration and still get a meaningful answer? Explain your answer

in a few sentences.

[2 Marks]


d. If it takes 25 mL of 0.05 M HCl to neutralize 345 mL of NaOH solution, what is

the concentration of the NaOH solution?

[2 Marks]

e. If it takes 50 mL of 0.5 M KOH solution to completely neutralize 125 mL of

sulfuric acid solution (H2SO4), what is the concentration of the H2SO4 solution?

[2 Marks]

---------------------------------------END OF SECTION C -----------------------------------


SECTION D: PHYSICS

STRUCTURE QUESTIONS

[20 marks]






THE RELATIONSHIP BETWEEN TEMPERATURE (°C) AND ICE CREAM

SALES ($)

Objective: To obtain the best line fitting of the relationship between the temperature

°C and ice cream sales $.

The local ice cream shop keeps track of how much ice cream they sell versus the

temperature on that day. Here are their figures for the last 10 days:

Temperature (°C) Ice cream sales ($)

20.2 395

26.4 475

21.9 418

15.2 320

28.5 500

22.1 435

19.4 380

25.1 458

23.4 440

18.1 337

a) Draw the best line graph to see that warmer weather leads to more sales.

(10 marks)

b) Determine the sales when the temperature is 27.0 °C

(1 marks)

c) Determine the y-intercept

(1 marks)

d) Calculate the gradient of the straight line graph

(4 marks)

e) Calculate the average of ice cream sales for 10 days

(4 marks)

---------------------------------------END OF SECTION D -----------------------------------

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Basic Laboratory Skills Model Exam Paper