Sci Methodology
Lab safety
Solutions
100
1. Make observations
2. Construct a hypothesis
3.Design and perform an experiment to test the hypothesis
4. Develop a theory
What are the general steps in a scientific method?
100
The document that is refered to before starting any experiment in the lab. It contains information regarding storage, handling and PPE to be used, first aid measures if exposed to a particular chemical.
What is MSDS or Material Safety data sheets?
100
The molarity of a solution is defined as the number of moles of solute per liter of solution. The symbol for molarity is M, but it can also be written as moles/Liter, or mol/L.
What is molarity? What is the symbol for molarity and how is it represented?
200
A scientific theory allows scientists to predict and describe the underlying causes of physical behavior. A theory is the result of an experimentally supported hypothesis that has been tested extensively.
What is a scientific theory?
200
There are 16 sections on the MSDS, like first aid measures, ecological and toxicological information.
How many sections does a MSDS have and mentions 3 of them?
200
A mole of any element always contains 6.02 X 1023 (Avogadro’s number) atoms.
Because some atoms are heavier than others, a mole of one element weighs a different amount than a mole of another element
What is a mole and why is the mole of an element different from another?
300
A scientific law is a brief statement that summarizes past observations and theories in order to predict future behavior. For example, A law does not offer much of an explanation for the behavior; it just gives a condensed summary of the observations.
What is a scientific law?
300
GHS or Globally Harmonized System is a system for harmonizing hazard classification criteria and chemical hazard communication elements worldwide.
What is a GHS label?
300
We can’t directly measure moles, but we can measure mass. To calculate the mass of a chemical needed to prepare a given volume of a solution of desired molarity, you must convert number of moles to mass, using the chemical’s molar mass as a conversion factor.
Why is moles converted to mass of a substance?
400
Mass of a compound decreases as reaction proceeds is _________________observation.
Whether a qualitative or quantitative observation?
400
GHS label has 6 elements and signal word is the 1st part of the label which indicates the hazard level.
How many elements are on a GHS label and what does a signal word mean?
400
C1V1 = C2V2
To dilute a more concentrated stock solution to a less concentrated solution, the following formula is used:
500
Student planted tomato seeds in the pots and left them at the windowsill, watering them once every three days and one wasn’t watered at all.
Example of a control in an experiment?
500
Nver return unused chemical back to the container.
If you have poured additional amount of a chemical than that is normally needed for your experiment, what would you do after you realise it?
500
Look it up in a periodic table.
Where can you find atomic mass for an element?