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