Lab Report DEPARTMENT MA ABAH

FACULTY OF SCIENCE AND NATURAL RESOURCES

SCIENCE COMPLEX

BIOTECHNOLOGY PROGRAMME (HG07)

SEMESTER 1 2019/2020

LABORATORY REPORT 1

NAME : MILA ATIQAH BINTI MANSUR

MATRIC NO. : BS19110062

TITLE : PREPARING SOLUTIONS

LECTURER’S NAME : ASSOC. PROF. DR. ZALEHA ABDUL AZIZ

DEMONSTRATOR NAME : FLORISA LANDA

SUBJECT : BASIC BIOTECHNOLOGY (SY12103)

DATE OF EXPERIMENT : 24 SEPTEMBER 2019

DATE OF SUBMISSION : 15 OCTOBER 2019

INTRODUCTION

A solution is defined as a homogenous mixture of two or more substance which may

exist in any phase. It also consists of a solute and a solvent. A solute is a substance that

dissolved in the solvent and the amount of solute that can be dissolved in solvent is called its

solubility (Anne, 2019). When two liquids dissolve in each other, the major component is called

the solvent and the minor component is called the solute. There are three types of solutions

which are gaseous, liquid and solid solutions. Meanwhile a dilution is a solution made by

adding more solvent to a more concentrated solution which called a stock solution and this

will reduces the concentration of the solute. For instance, tap water is a dilute solution because

it is mostly water with a small amount of dissolved minerals and gasses.

There are so many different measures of solution concentration that exist because

these solutions play important roles in any reaction, especially in biotechnology and chemistry

field. Usually, the solutions are prepared at a particular concentration to ensure an optimal

condition for a reaction to occur. The concentration of solution can be measured by a few

units of expression such as Molarity (M), Molality (m), Normality (N) and parts per million

(ppm). Molarity is defined as the number of moles of solute per litre of solution. Meanwhile,

molality is the number of moles of solute per kilogram of solvent and normality is the number

of mole equivalents per litre of solution. Although their spellings are similar, molarity and

molality cannot be interchanged. Molarity is a measurement of the moles in the total volume

of the solution, whereas molality is a measurement of the moles in relationship to the mass

of the solvent (Carolina, 2018). When the solute is present in trace quantities, it is easy to

express the concentration of solutions in parts per million (ppm). In samples of water from

the environment, for example, concentrations of metal ions can be in the range of a few parts

per million — it is impractical and potentially misleading to express this tiny concentration as

a molarity or mole fraction. Although molarity is a convenient measure of concentration for

stoichiometry calculations involving chemical reactions, molality is more appropriate in studies

of certain colligative properties (Moshe, 2019).

OBJECTIVES

1. To be able to prepare solutions at various concentrations.

2. To be able to explain different types of units used in expressing the concentrations of

solutions.

EQUIPMENTS

• Ten millilitre glass pipette

• Two millilitre glass pipette

• Beakers ( one hundred millilitre )

• Magnetic stirrer

• Magnetic bars

• Pipette filter

• Analytical balance

• Aluminium foil

• Spatula

• Volumetric flasks ( one hundred millilitre, two hundred fifty millilitre and five hundred

millilitre )

• Glass rods

MATERIALS

• Sodium hydroxide (NaOH)

• Distilled water

• Acetic acid

• Hydrochloric acid (HCl)

PROCEDURE

A. Preparing solution in molar solution = the number of moles of solute per

litre of solution

1. Ten grams of sodium hydroxide was dissolved in water using a two hundred

and fifty millilitre capacity beaker.

2. The mixture was stirred using a glass rod to dissolve the palette.

3. The bottom of the beaker was touched to feel the warmth before being

transferred into a two hundred and fifty millilitre volumetric flask and the

beaker was rinsed three times with distilled water.

4. The rinsed water was poured into the volumetric flask to be filled up until the

bottom of the meniscus is levelled to the calibration line on the flask.

5. The flask was inverted and swirled a few times to mi the content.

6. The solution was transferred into a clean and dry blue capped glass bottle.

7. The solution was labelled with its name, concentration and the date it was

prepared.

B. Preparing solution in Percent solution

1. Five millilitre concentrated acetic acid was pipetted out by placing the tip of the

pipette on the inner wall of the beaker and the acid was slowly trickled down into

a fifty millilitre water in a beaker.

2. The diluted acid was transferred into a one hundred millilitre volumetric flask and

the beaker was rinsed three times with distilled water before being the rinsed

water being poured into the volumetric flask.

3. The flask was filled up until the specified level by using deionised water from

squeeze bottle.

C. Diluting a concentrated solution (Dilution)

1. The volume and molar concentration of the resulting solution was decided before