A - The mass of the cents

Cents Weighed Mass Mass by Difference Difference
#1 1.73g 1.73g 0g
#2 1.72g 1.72g 0g
#3 1.72g 1.72g 0g
#4 1.73g 1.73g 0g
#5 1.73g 1.73g 0g
Total mass 8.63g
Total mass - #5 6.90g
Remaining mass - #4 5.17g
Remaining mass - #3 3.45g
Remaining mass - #2 1.73g
Remaining mass - #1 0g

Mass by difference = Total mass - ( Total mass - #5 )
= 1.73g

Difference = Weighed mass - mass by difference
= 1.73g - 1.73g
= 0g

Mean = 1.73 + 1.72 + 1.72 + 1.73 + 1.73

= 8.63 / 5
= 1.73

Mass Mean Mass - Mean ( Mass - Mean )2
1.73 1.73 0 0
1.72 1.73 ( -1 ) 1
1.72 1.73 ( -1 ) 1
1.73 1.73 0 0
1.73 1.73 0 0
Standard deviation =

= 0 + 1 + 1 + 0 + 0
= 0.4

B - The accuracy of the micropipettes

Volume of distilled water (µl) (Expected result) Weight of distilled water (mg) (Obtained result) Percentage of micropipettes
100 0.11mg 0.11%
500 0.50mg 0.10%
1000 1.01mg 0.10%
Your selected volume ( 900 ) 0.90mg 0.10%

Percentage = 0.11mg
X 100%
= 0.11%

C - Plotting an absorbance spectrum

Wavelength ( nm ) Absorbance 1 Absorbance 2* Average of absorbance
540 0.630 0.617 0.624
560 0.553 0.548 0.551
600 0.582 0.585 0.584
610 0.623 0.616 0.620
620 0.618 0.613 0.616

Analytical thinking is a critical component of visual thinking that gives one the ability to solve problems quickly and effectively. It involves a methodical step-by-step approach to thinking that allows to solve a problem. Gathering relevant information and identifying key issues related to this information are processes of analytical thinking. This type of thinking also requires to compare sets of data from different sources. An analytical thinker usually will identify possible cause and effect patterns, and draw appropriate conclusions from these datasets in order to achieve appropriate solutions. Analytical thinking is important to look at something through different points of view with the objective to create a cause and an effect. Other than that, with analytical thinking, facts can be used to support the conclusion and train of thought. Analytical thinking lead us to have a more focus and stream-lined approach to solution finding. Micropipettes are designed to transfer and measure very small amounts of liquid. They can used to measure volume as low as 0.1 microlitre. Micropipettes require disposable tips that come in contact with the fluid. Micropipettes come in many sizes. The most commonly used micropipettes in laboratory are the P-10, P-20, P-200 and P-1000. The number refers to the maximum volume ( measure in microlitre ) that can be transfered. The four standard sizes of micropipettes correspond to four different disposable tip colors. P-10 is white in color, P-20 and P-200 are yellow in color and P-1000 is blue in color. Balances are designed to meet the specific weighing requirement in the laboratory. These balances come in precision designs and operating characteristics that allows making quick and accurate measurements. There are many types of balances can be found in laboratory. Electronic balance, analytical balance and precision weighing balance are the most commonly used balances. Electronic balances provides their results in digital, making them an easy tool to be used. Analytical balances come with the highest accuracy for meeting the demands of analytical weighing processes. Precision weighing balances are laboratory standard high precision balances that are based on latest process technology and features best displayed increment of 0.001g (1mg) with maximum capacity available. A spectrometer is any instrument used to probe a property of light as a function of its portion of the electromagnetic spectrum, typically its wavelength, frequency, or energy. The property being measured is usually intensity of light, but other variables like polarization can also be measured. there are four types of spectrometer which are optical spectrometer, mass spectrometer and time-of-flight spectrometer. Optical spectrometer show the intensity of light as a function of wavelength or of frequency. Mass spectrometer is used to identify the amount and type of chemicals present in a sample. Further, time-of-flight spectrometer is used to determine the time of flight between two detectors so that energy spectrum of of particles of known mass can be measured.


As a conclusion, it is very important to be a analytical thinker in order to solve problems that we are facing in daily life. Other than that, as a science students, we should know how to handle an equipment appropriately for the correct usages. Further, proper lab technique skills must be practiced in order to get accurate result for an experiment and also to avoid any accidents.


1. One of the lab equipment that we commonly use in laboratory is autoclave. An autoclave is a pressure chamber used to sterilize equipment and supplies by subjecting them to high pressure . Pressure applied is usually 121’C and the time is depends on the size of the loads and the contents. Autoclave is usually involves in the pre-disposal treatment