DIRECTION: Choose the correct answer and write the letter of your choice on the space provided.

__________1. How do you prepare a buffer solution?A)By mixing the solutions of a strong acid and a weak acid.B)By mixing the solutions a strong base with the solution of its

salt.C)By mixing the solutions of a weak acid and a weak base.D) By mixing the solution of a weak acid with the solution of its

salt.E)All of the above.

__________2. A freshman chemist analyzed a sample of copper(II) sulfate pentahydrate for water of hydration by weighing the hydrate, heating it to convert it to anhydrous copper(II) sulfate, and then weighing the anhydride. The % H2O was determined to be 30%. The theoretical value is 33%. Which of the following choices is definitely NOT the cause of the error?

A)After the student weighed the hydrate, a piece of rust fell from the tongs into the crucible.

B)Moisture driven from the hydrate condensed on the inside of the crucible cover before the student weighed the anhydride.

C)The original sample was wet.D) All the weightings were made on a balance that was high by

10%.E)The original sample contained some anhydrous copper(II)

sulfate.__________3. Dilution of a concentrated solution involves

A)maintaining the amount of the solvent constant.B) maintaining the amount of the solute constant.C) reducing the amount of the solute while keeping the volume of the solution

constant.D)reducing the volume of the solvent while keeping the amount of the solute fixed.E) all of the above.

__________4. The equivalent weight of an acid is A)the mass of the acid that reacts with exactly one gram of a base.B) the mass of the acid that reacts with exactly one mole of a base.C) the mass of the acid that reacts with exactly one mole of H+-ions.D)the volume of the acid that reacts with exactly one mole OH--ions. E) None of the above.

__________5. At the equivalent point of the titration of an acid against a baseA)the number of moles of the acid is equal to the number moles of the base.B) the volume of the acid is equal to the volume of the base.C) the number of equivalent of the acid is equal to the number of equivalent of the

base.D)the molarity of the acid is equal to the molarity of the base.E) None of the above.

__________6. When mixing a strong acid with waterA)the water should be added to the acid.

DEFENCE ENGINEERING COLLEGEDEPARTMENT OF CHEMICAL ENGINEERING

EXAMINATION FOR CANDIDATES COMPETEING FOR THE POST OF CHEMISTRY LABORATORY TECHNICIAN

NAME:

B) the acid should be added to the water.C) either of the two can be added to the other one.D)a strong acid should not be mixed with water.E) None of the above.

__________7. All of these changes indicate that a reduction has occurred exceptA)increase in oxidation numberB) gain of electronsC) electrons as reactantsD)reactant acting as an oxidizing agentE) pure oxygen becoming oxide ion

__________8. For reaction 2N2O5 2 NO2 + O2, the rate and rate constants are 1.02 x10-4 mole litre-1 sec-1 and 3.4x10-5 sec-1 respectively. The concentration of N2O5 at that time will be:A)1.732 mol lit-1

B) 3 mol lit-1C) 1.02×10-4 mol lit-1

D)3.2×105 mol lit-1

__________9. The mass in miligrams of a titrand (substance titrated) that reacts with exactly one mililiter of a titrant is referred to as itsA)equivalent weightB) molar massC) titer

D)number of equivalents.E) None of the above.

__________10. Which of the following units of concentration is independent of temperature?A)molarityB) molalityC) normality

D)formality E) density

__________11. Ethanoic acid dimerises in solution. Its molecular mass determined from its depression of freezing point of the solution will be:A)Same as the theoretical valueB) Half its theoretical value

C) Double its theoretical valueD)One third of its theoretical value.

__________12. The measured mass of a sample of iron was 1.23 g. Which digit in the measurement has the least certainty?A)the first digit, 1B) the middle digit, 2

C) the last digit, 3D)They are all certain digits

__________13. The reaction between the ion of a weak acid or a weak base and water is called a(an) _____reaction.A) neutralizationB) autoionizationC) protonation

D)hydrolysisE) decomposition

__________14. Which one of the following represents an intensive property?A)temperatureB) massC) volume

D) lengthE) heat capacity

__________15. Which of the following is a conjugate acid-base pair?A)H+ and OH-

B)CH3COOH and CH3COO-

C)CH3COOH and OH-

D) CH3COOH and H+

E) CH3COOH and H3O+

__________16. The combustion of carbon monoxide yields carbon dioxide. The volume of oxygen gas needed to produce 22 grams of carbon dioxide at STP isA) 4.0 litersB) 5.6 liters

C) 11 litersD) 22 liters

E) 32 liters__________17. When 2.00 grams of a certain volatile liquid is heated, the volume of the

resulting vapor is 821 mL at a temperature of 127°C at standard pressure. The molecular weight of this substance is

(R= 0.0821 L.atm/mol. K)A) 20.0 g/moleB) 40.0 g/moleC)80.0 g/mole

D) 120. g/moleE)160. g/mole

__________18. The measuring unit one part per million is equivalent toA)one mg solute/kg solutionB) one ng solute/kg solutionC) one úg solute/kg solution

D)one kg solute/ng solutionE) one kg solute/mg solution

__________19. How many milliliters of a 50.0% (by mass) HNO3 solution, with a density of 2.00 grams per milliliter, are required to make 500. mL of a 2.00 M HNO3 solution?A)50.0 mLB) 63.0 mLC) 100. mL

D)200. mLE) 250. mL

__________20. A negative sign is included in the expression for the rate of disappearance of a reactant becauseA) the value of [reactant] is positive as calculatedB) reaction rate is defined as a positive quantityC) it cancels out the negative value of t in the denominatorD) the change in concentration can never be zeroE) the coefficients in the balanced equation can never be negative

__________21. Which of the following factors increases the rate of a chemical reaction by decreasing the activation energy barrier?

A) increasing the temperatureB) increasing the concentration of reactantsC) increasing the concentration of productsD) adding a catalystE) increasing the surface area of a phase interface

__________22. The maximum amount of a substance that dissolves in a given amount of solvent at aspecified temperature is the _____ of the substance.

A) concentrationB) molarityC) solubility

D) lattice energyE) density

__________23. Which of the following contributes to the acidity of the hydrogen atom in the carboxylic acid functional group?

A) the electronegativity of the O that is bonded to the HB) the attraction of the other atom of O for the electrons in the O-H bondC) resonance stabilization of the resulting anionD) the lack of polarity in the C-H bonds in the rest of the moleculeE) All of these

__________24. relationship between pressure and solubility of a gas is calledA) the Law of Conservation of Mass.B) the First Law of Thermodynamics.C) the Second Law of Thermodynamics.D) Henry’s Law.E) the solubility rules.

__________25. The association between a Lewis acid and a Lewis base is called a(an) _____ bond.A) acidic B) coordinate covalent

C) hydrogenD) ionic

E) metallic

__________26. Which property does not enhance the usefulness of sodium as a heat transfer medium in nuclear reactors?

A) It has a very low melting point.B) It has an unusually high heat capacity.C) It is extremely reactive toward water.D) It has a high thermal conductivity.E) It can easily be liquefied.

__________27. What is the normality of a solution that contains 9.80 g of H2SO4 in 200. mL of solution, assuming 100% ionization of H2 SO4?

A) 0.500 NB) 1.00 NC) 1.50 N

D)2.00 NE) 2.50 N

Interview Questions

Questions Point2 4 6 8 10

1. Tell us about yourself.

2. Tell us about your experience related to this type of work.

3. Why do you want to work here?

4. Why did you leave your last job?

5. Why did you leave your last job?

6. What kind of salary do you need?

7. Wow is your health?

8. When are available for work?

9. What are your greatest strengths?

10. What are your weaknesses?

11. What was your last employer's opinion of you?

12. What are your long-range goals?

13. What kind of machines or equipment have you worked with?

14. Can you work under pressure or tight deadlines?

15. Are thinking of going back to school or college?

16. What is your greatest achievement?

17. How long have you been out of work?

18. How often have you changed jobs?

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