CHEMISTRY LAB EXAM 5 EXAMINATION
TEST FINAL PAPER FULL SOLUTION 2026
GRADED A+.
⫸ What effect would increasing the temperature have on the position
of the white ring and the time required for the ring to appear in the
glass tube. Answer: -the position of the ring would not change, the
velocity of both gases would increase equally
-the time would be shorter, because the white ring forms quicker
⫸ Why does it take so much time for the white ring to appear?
Answer: The gases must meet and NH4Cl needs to build up
⫸ Does the first appearance of the white ring of NH4Cl indicate the
first contact of NH3 molecules with HCl molecules? Answer: No,
time is required for the amount of NH4Cl to build up, making the
white ring visible
⫸ Calculate the distances known gases should move. Calculate the
distances (in cm) NH3 gas and HCl gas would travel in the diffusion
experiment if a 50.0 cm tube were used. Answer: Equation: distance
traveled/secs
⫸ Determine the molar mass and identity of the unknown gas.
Answer: Equation: (rate A/rate B)=√(mass B/mass A)
, ⫸ Suppose that the NH3-saturated cotton plug were inadvertently
placed in the tube before the HCl-saturated cotton plug. How would
this change (1) the distance that the HCl and the NH3 traveled, (2)
their rates of effusion, (3) the calculated molar masses and (4) the
position of the white ring? Answer: (1) the NH3 would travel farther
and the HCl not so much
(2/3) the rate of NH3 would be higher and HCl would be slower
(4) the ring would be closer to the HCl side
⫸ At 0°C, the root mean square velocity of hydrogen gas, H2, is
approximately 4100 mph. Calculate the root mean square velocity of
oxygen gas, O2, at 0°C. Answer: Equation: (rate A/rate B)/√(rate
B/rate a)
Answer: 1030mph
⫸ A rubber balloon was inflated with hydrogen gas, H2. A few hours
later, the balloon was observed to be practically deflated. What
happened? If the balloon had been filled with oxygen gas, O2, would
it have been as deflated in the same time? Answer: H2(g) is passing
through the pores of the balloon, resulting in the deflating. The heat
leaves faster than O2 enters. O2 has a more difficult time passing
through due to the size and it hits the inside surface of the balloon less
often.
⫸ Would the calculated molar volume of a gas be incorrectly larger
or smaller or not changed if... too much dry ice was added to the
flask..... after determining the mass of the flask, stopper, and air, the
student used a stopper with less mass than the original stopper when
TEST FINAL PAPER FULL SOLUTION 2026
GRADED A+.
⫸ What effect would increasing the temperature have on the position
of the white ring and the time required for the ring to appear in the
glass tube. Answer: -the position of the ring would not change, the
velocity of both gases would increase equally
-the time would be shorter, because the white ring forms quicker
⫸ Why does it take so much time for the white ring to appear?
Answer: The gases must meet and NH4Cl needs to build up
⫸ Does the first appearance of the white ring of NH4Cl indicate the
first contact of NH3 molecules with HCl molecules? Answer: No,
time is required for the amount of NH4Cl to build up, making the
white ring visible
⫸ Calculate the distances known gases should move. Calculate the
distances (in cm) NH3 gas and HCl gas would travel in the diffusion
experiment if a 50.0 cm tube were used. Answer: Equation: distance
traveled/secs
⫸ Determine the molar mass and identity of the unknown gas.
Answer: Equation: (rate A/rate B)=√(mass B/mass A)
, ⫸ Suppose that the NH3-saturated cotton plug were inadvertently
placed in the tube before the HCl-saturated cotton plug. How would
this change (1) the distance that the HCl and the NH3 traveled, (2)
their rates of effusion, (3) the calculated molar masses and (4) the
position of the white ring? Answer: (1) the NH3 would travel farther
and the HCl not so much
(2/3) the rate of NH3 would be higher and HCl would be slower
(4) the ring would be closer to the HCl side
⫸ At 0°C, the root mean square velocity of hydrogen gas, H2, is
approximately 4100 mph. Calculate the root mean square velocity of
oxygen gas, O2, at 0°C. Answer: Equation: (rate A/rate B)/√(rate
B/rate a)
Answer: 1030mph
⫸ A rubber balloon was inflated with hydrogen gas, H2. A few hours
later, the balloon was observed to be practically deflated. What
happened? If the balloon had been filled with oxygen gas, O2, would
it have been as deflated in the same time? Answer: H2(g) is passing
through the pores of the balloon, resulting in the deflating. The heat
leaves faster than O2 enters. O2 has a more difficult time passing
through due to the size and it hits the inside surface of the balloon less
often.
⫸ Would the calculated molar volume of a gas be incorrectly larger
or smaller or not changed if... too much dry ice was added to the
flask..... after determining the mass of the flask, stopper, and air, the
student used a stopper with less mass than the original stopper when
