Using an oscilloscope, it can be observed that the pitch of a sound is directly related to a sound wave’s frequency while the volume is directly related to a sound wave’s amplitude. the change shown in the illustration suggests that the a) pitch is increasing. b) pitch is decreasing. c) volume is increasing. d) volume is decreasing.

Your answer is D.

The change in the illustration shows a decrease in amplitude. Because a sound wave’s amplitude is directly related to a sound’s volume, the change in the wave tells us that the volume is decreasing.

First, we will use the ideal gas law to determine the number of moles of the mixture that was present.

n = PV/RT

n = 1 * 5.04 / 0.082 * (273.15 + 0)
n = 0.225 moles

Let the moles of propane be P and the moles of methane be M.

P + M = 0.225

Next, we find the moles of carbon dioxide formed:

Moles = mass / Molecular weight
Moles = 19.4 / 44 = 0.441

Each mole of propane produces 3 moles of carbon dioxide and each mole of methane produces one mole of carbon dioxide. So:

3P + M = 0.441

Subtracting the first equation from the second, we get:

2P = 0.216
P = 0.108 moles

M = 0.225 - 0.108
M = 0.117

Fraction of propane = 0.108/0.225 = 0.48
Fraction of methane = 0.52