Chem 1a Labflow Questions With Complete Solutions
7.298 g sample of copper reacts with oxygen, forming a copper
oxide. The final mass of the copper oxide is 8.217 g.
What is the formula of the copper oxide? Correct Answers
Cu2O
A balloon is inflated outside on a cool morning. As the
temperature rises, reaching its peak in the afternoon, the volume
of the balloon will ___ . As the temperature cools down again in
the evening, the volume of the balloon will ___ Correct
Answers increase, decrease
A calorimeter measures the ___ involved in reactions or other
processes by measuring the ___of the materials ___ the process.
The calorimeter is ___ to prevent transfer of heat to outside the
device. Correct Answers heat, temperature change,
surrounding, insulted
a concentrated salt solution has a mass of 5.33g for a 5.00mL
sample, what is the specific gravity of this solution? Correct
Answers 1.066
specific gravity=density of substance/density of water
a hydrometer is a tool used to measure the ___ of a liquid
relative to that of ___ Correct Answers density, water
a reagent added to the analyte solution that changes color when
the reaction is complete Correct Answers indicator
,A sample of gas is subject to changes in conditions. Predict the
effect of each change. Correct Answers The pressure and the
temperature are both decreased by 50%. What will happen to the
volume? - stay
The volume and temperature remain constant, while some of the
gas is let out of the container. What will happen to the
pressure?- decrease
The pressure and volume are increased. What will happen to the
temperature? - increase
The pressure is kept constant, while the temperature is
decreased. What will happen to the volume? - decrease
a student performed a density experiment in triplicate and
recorded the data shown. calculate the average density (in g/mL)
for this experiment
trial 1: 2.99 g/mL
trial 2: 2.82 g/mL
trial 3: 2.85 g/mL Correct Answers 2.89 g/mL
sum the values and divide the sum by the number of values
At the freezing point, the liquid form of a substance ___ the
solid form of the substance. Correct Answers is in equilibrium
with
before running a titration , you calculate the expected endpoint.
However, when performing the experiment, you pass the
expected endpoint with no visible color change. what is most
likely the problem with the titration set up? Correct Answers
there is not enough indicator in the analyte
Between flame tests, the nichrome wire is cleaned.
, What color should appear when a properly cleaned nichrome
wire is introduced into the flame? Correct Answers light or
faint yellow
calculate the mass percent of a vinegar solution with a total mass
of 96.41 g that contains 2.80 g of acetic acid Correct Answers
2.904
% mass = mass of solute/mass of solution x 100
Calculate the moles of ammonia present in a 3.067 g sample if
the molar mass of ammonia is 17.030 g/mol. Correct
Answers .1801
moles of substance=mass in g×1 molE of substance/molar mass
Changing gloves often will minimize the spread of chemicals.
To properly remove gloves, first ___ and then, ___ then insert,
___ between the interior edge of the second glove and the skin,
and remove the second glove. Correct Answers grasp the
exterior of one glove with a gloved hand peel off the first glove
a bare finger
choose the best graduated cylinder to make each measurement in
a single use Correct Answers 36 mL of water - a 50 ml with
markings every 10 mL
18.5 mL of a NaCl solution- 25 mL with markings every 1mL
5.75 mL of a sucrose solution - 10 mL with markings every .1
mL
Choose the most appropriate task for each pictured glassware
Correct Answers flask (cone shaped) - containing a stirred
reaction mixture
7.298 g sample of copper reacts with oxygen, forming a copper
oxide. The final mass of the copper oxide is 8.217 g.
What is the formula of the copper oxide? Correct Answers
Cu2O
A balloon is inflated outside on a cool morning. As the
temperature rises, reaching its peak in the afternoon, the volume
of the balloon will ___ . As the temperature cools down again in
the evening, the volume of the balloon will ___ Correct
Answers increase, decrease
A calorimeter measures the ___ involved in reactions or other
processes by measuring the ___of the materials ___ the process.
The calorimeter is ___ to prevent transfer of heat to outside the
device. Correct Answers heat, temperature change,
surrounding, insulted
a concentrated salt solution has a mass of 5.33g for a 5.00mL
sample, what is the specific gravity of this solution? Correct
Answers 1.066
specific gravity=density of substance/density of water
a hydrometer is a tool used to measure the ___ of a liquid
relative to that of ___ Correct Answers density, water
a reagent added to the analyte solution that changes color when
the reaction is complete Correct Answers indicator
,A sample of gas is subject to changes in conditions. Predict the
effect of each change. Correct Answers The pressure and the
temperature are both decreased by 50%. What will happen to the
volume? - stay
The volume and temperature remain constant, while some of the
gas is let out of the container. What will happen to the
pressure?- decrease
The pressure and volume are increased. What will happen to the
temperature? - increase
The pressure is kept constant, while the temperature is
decreased. What will happen to the volume? - decrease
a student performed a density experiment in triplicate and
recorded the data shown. calculate the average density (in g/mL)
for this experiment
trial 1: 2.99 g/mL
trial 2: 2.82 g/mL
trial 3: 2.85 g/mL Correct Answers 2.89 g/mL
sum the values and divide the sum by the number of values
At the freezing point, the liquid form of a substance ___ the
solid form of the substance. Correct Answers is in equilibrium
with
before running a titration , you calculate the expected endpoint.
However, when performing the experiment, you pass the
expected endpoint with no visible color change. what is most
likely the problem with the titration set up? Correct Answers
there is not enough indicator in the analyte
Between flame tests, the nichrome wire is cleaned.
, What color should appear when a properly cleaned nichrome
wire is introduced into the flame? Correct Answers light or
faint yellow
calculate the mass percent of a vinegar solution with a total mass
of 96.41 g that contains 2.80 g of acetic acid Correct Answers
2.904
% mass = mass of solute/mass of solution x 100
Calculate the moles of ammonia present in a 3.067 g sample if
the molar mass of ammonia is 17.030 g/mol. Correct
Answers .1801
moles of substance=mass in g×1 molE of substance/molar mass
Changing gloves often will minimize the spread of chemicals.
To properly remove gloves, first ___ and then, ___ then insert,
___ between the interior edge of the second glove and the skin,
and remove the second glove. Correct Answers grasp the
exterior of one glove with a gloved hand peel off the first glove
a bare finger
choose the best graduated cylinder to make each measurement in
a single use Correct Answers 36 mL of water - a 50 ml with
markings every 10 mL
18.5 mL of a NaCl solution- 25 mL with markings every 1mL
5.75 mL of a sucrose solution - 10 mL with markings every .1
mL
Choose the most appropriate task for each pictured glassware
Correct Answers flask (cone shaped) - containing a stirred
reaction mixture
