Chem Lab Final (CCM)
analytical balance
+/- 0.0001 gram
trible beam balance
+/- 0.1
safety data sheets (SDS) include
- health information - safety information - first-aid information - and disposal information about al chemicals and compound in the lab
beat wavelength to run bromphenol blue is
600 nm
which of the following statements concerning accuracy and precision is/are correct: I. It is possible for a series of measurements to be both precise and inaccurate II. Accuracy is a measure of how close multiple measurements are close to each other III. The greater the number of sig figs in measurement the more accurate the measurement is
I
explain bases on the electronic structure, why metals near the bottom of group 1 are more reactive than metals near the top of group 1
group one metals are more reactive going down because their valence electrons are further from the nuclei. This means the nucleus has less of a hold on the electron so it can easily be taken and use in a reaction
never pour water into what
into a concentrated acid
why is the methylene chloride layer the bottom layer
it is more dense
Density
mass (g) /volume (ml)
which pipette was more accurate in the pipette lab
neither because we did not know the standard weight of the substance
which pipette was more precise
pipette A because it had a lower standard of deviation compared to pipette B
to calculate density of a solid the liquid must not
react with the solid as well as be less dense
Archimedes' Principle
states that when a solid object is placed in a liquid the solid displaces its own volume of liquid
read the label on the bottle
twice
always pour acid slowly into
water
density graph
x axis = volume of liquid (mL) y axis = mass (g)
the law of mass conservation
all changes in matter take place on a definite mass or weight basis
which balance is more precise
analytical balance
Hazcom's (law) three main points
1) employers must list all hazardous substances present in the workplace 2) chemicals must be labeled properly 3) employers must collect a safety data sheet (SDS) for all hazardous substances and make then available for their employees
explain the order of activity in the halogen family of the basis of the electronic structure of these elements
The halogens activity is measure by both radius size and ability to gain electrons. Fluorine is the most active because its radius is the smallest and has a greater pull, while Iodine is the least because its pull is weaker and has bigger radius