Gen Chem 1 Lab Final
General guidelines for preventing accidents include:
A. follow all safety instructions carefully B. know where the safety equipment is C. never play tricks or indulge in horseplay in the chemical laboratory D. become familiar with the hazards of equipment to be used E. become familiar with the hazards of the chemicals to be used
chemical spills can be prevented by:
A. keeping laboratory items well away from the edge of your laboratory bench. B. measuring quantities of chemical according to the laboratory procedure and not taking excess chemicals. C. notifying your instructor if you observe obstructions in the aisles or walkways of the laboratory space. D. walking slowly and carefully in the laboratory. E. supporting the beaker or flask with one hand under the container if you need to transport samples or solutions from one part of the lab to another.
What terms are signal words found on a GHS label?
Danger and Warning
How will we measure the volume of hydrogen gas generated?
Determining the volume of water displaced by hydrogen gas
Systematic error can be eliminated by collecting many data points and averaging.
False
True or False: It is okay to wear safety glasses that have small gaps around the top, sides and bottom
False
True or False: Pouring from bigger containers is safer
False
True or False: You are permitted to bring food and drink into the lab as long as it's packaged and you don't eat or drink it while in the lab
False
True or False: a lab thermometer has to be shaken down like medical thermometers.
False
Required attire in the lab includes
Full coverage safety goggles, Long pants, Disposable gloves, Lab coat, Closed-toe shoe
analytical balances
Have greater precision than top-loading balances. Are in a glass enclosure to minimize the effect of air movement.
Which elements generally have positive electron affinities?
Noble gases
Which of the following is a chemical property? Check all that apply:
Reactivity with water
What does RAMP stand for?
Recognize hazards, Assess the risks of hazards, Minimize the risks of hazards, Prepare for emergencies
What does SDS stand for?
Safety Data Sheet
Why do we need to equalize the water levels after the reaction?
To equalize the pressure inside and outside the flask
You find a beaker filled with an unknown clear liquid on your desk, what should you do?
Treat the liquid as hazardous; inform your instructor so that you can be notified of the proper disposal technique
Proper lab attire: Feet must be completely covered, and no skin should be showing between the top of the shoe and the bottom of the skirt or pants. True/ False
True
True or False: A saturated solution contains undissolved solute at equilibrium.
True
True or False: All students working in the laboratory are responsible for planning and carrying out each experiment in a manner that will ensure a safe environment to everyone in the facility and with care for university property.
True
True or False: Before using a chemical, you must learn its properties and hazards.
True
True or False: If your gloves become contaminated, you should replace them immediately.
True
True or False: In general, smaller atoms are more electronegative.
True
True or False: You must read all procedures thoroughly before entering the lab.
True
True/ False: Full splash-proof goggles must be worn from the moment you start working in the lab till you leave
True
a small standard deviation indicates high precision
True
Every graph you prepare must show the following features:
Visible data points, Axes labels including units, Descriptive title, Your name and date, Appropriate scale
Would you expect a small piece of aluminum oxide to have the same density as a large piece?
Yes, I would; density is an intensive physical property.
If you come to class wearing shorts (short skirts) and flip flops...
You will need to change into closed-toe shoes and long pants, or you will not be permitted to perform the experiment.
What is a fume hood?
a lab device that allows us to experiment with volatile or noxious chemicals whiles isolating the vapors from the lab
Safety in the instructional lab is...
a shared responsibility
When a piece of sodium metal is dropped into a calorimeter filled with water, hydrogen gas evolves. The temperature of the mixture rises because...
an exothermic reaction occurs
The exceptions to the trend of ionization energy are due to...
an increase in shielding by electrons in different sublevels, Hund's rule
Erlenmeyer flasks
are not volumetric glassware
If you do not understand a part of a lab procedure, you should...
ask the instructor before proceeding
The electron-sea model describes metals as...
cations in a sea of valence electrons
Constant-pressure calorimetry is commonly carried out in a
coffee cup
If an endothermic reaction occurs in a calorimeter, the contents of the calorimeter is...
cool
Improper waste disposal can result in...
damage to the environment, adverse reactions leading to fires or explosions, legal issues for your institution
A gallium atom is slightly smaller than an aluminum atom due to...
effective shielding provided by electrons in the d sublevel
If the heat of a reaction is measured at constant pressure, it is equal to a change in
enthalpy
accidents often result from...
failure to use common sense, an indifferent attitude, failure to follow instructions, making mistakes
What is the best time to clean equipment and tools in the lab?
immediately after use
You must discard your lab coat...
in the regular trash
According to Charles' law, if the temperature of a gas increases, its volume...
increases and it is a direct relationship
In general, atomic radius __________ down a group and ___________ across a period from left to right.
increases, decreases
Across a period (from left to right), the nuclear charge __________ , and the number of electrons __________ .
increases, increases
What are possible ways for chemicals to enter the body?
ingestion, inhalation, absorption, injection
The effective nuclear charge
is smaller than the actual nuclear charge due to shielding provided by electrons.
Properties of metals
malleable, good thermal conductivity, high boiling points, good electrical conductivity
If a hot metal is dropped into a calorimeter filled with water, the q of the metal is... and the q of the water is...
negative, positive respectively
Which elements generally have highly negative electron affinities?
nonmetals (except noble gases)
If a lab fire erupts, immediately
notify your instructor
If you forget to remove bubbles from the tip of your buret, the volume of the titrant needed to reach the endpoint might be...
overestimated
What does SDS include about a chemical?
proper storage, proper disposal, identity, physical and chemical properties, physical health hazards and ingredients
What is not proper lab attire?
ripped jeans, short pants, cropped tops, tights
Filtration is useful for separating
solid from a liquid
Why do we use both the top-loading and the analytical balances in this experiment?
the analytical balance is used to measure the mass of Mg, while the top-loading balance is used to measure the mass of water displaced. B. We don't have enough top-loading balances.
In an acid- base titration, the end pint occurs when...
the indicator changes its color
In assignments and tests pertaining to the lecture, the calorimeter constant is used to calculate the heat absorbed by the calorimeter. In the laboratory,
we account for exchange of thermal energy with the calorimeter by extrapolation to the time of mixing.
What do we mean by waste minimization?
we do not return excess reagent to the reagent bottles, we only take the amounts of reagents necessary to complete the experiment, we dispose of proper waste containers, we try to us little reagent as possible
bromophenol blue is... in acidic solution and ... in basic solution
yellow, blue