1.Lab Safety Flashcards
What is a hazard?
A hazard is anything that poses a potential threat to individuals or environment. It can include toxic or corrosive, chemicals, heat or flammable substances, pathogenic organisms and mechanical equipment.
What is a risk?
Risk is the likelihood of harm arising from exposure to a hazard. a risk assessment, reduces the risk of Hazard.
What is a risk assessment?
A risk assessment involves identifying control measures to minimise the risk control measures include using appropriate handling techniques, protective clothing, equipment and aseptic technique.
What is linear dilution?
What are the dilution series difference by equal intervals for example, 0.1 0.2 0.3 et cetera
What is a log or serial dilution?
It differs by a constant proportion
What are the different equipment able to measure liquids?
Measuring cylinders, pipettes, buttered auto pipettes and syringes
What are colorimeter?
Colorimeters are devices that can be used to quantify concentrations.
What do colorimeters measure?
The absorbance of specific wavelengths of light by solution.
What can absorbance be used to determine?
The concentration of a coloured pigment
What can percentage transmission be used to determine?
Turbidity such as cells in suspension
What is a standard curve?
The standard curve is one method used to determine an unknown concentration of a solution.
What is pH?
pH is a measure of the acidity or basicity of a solution. It is a logarithmic measure of hydrogen ion concentration in a solution.
How can pH be measured?
By indicator or electronic meter
What are the advantages of using an indicator?
Maybe good for field usage or measuring small volumes are dealing with noxious samples
What are the disadvantages of using an indicator?
Less precise and each indicator is only good for a small pH range
What is the advantage of using electronic metres?
Accurate and can use data logging on computer
What is the disadvantage of using an electronic meter?
Need for frequent calibration
What is a pH buffer used for?
To control pH.
How can substance be separated using their physical properties?
Solubility, size/density, shape and charge
What is centrifugation?
Centrifugation is when a liquid is spun at very high speed for a period of time.
What is the use of a centrifuge?
The use of a centrifuge separate substances in the liquid by differing density.
Where does the largest and densest material separate and settle?
In the pellet at the bottom of the tube
What is the remaining liquid is known as above the pellet
Supernatant
