Question

standard temperature and pressure (stp) are considered to be 273 k and 1.0 atm. predict which of the following changes will cause the volume of the balloon to increase or decrease assuming that the temperature and the gas filling the balloon remain unchanged. drag the appropriate items to their respective bins. view available hint(s) reset help balloon filled with helium at stp floats into air where the pressure equals 1 atm balloon filled with helium at stp floats into the atmosphere where the pressure is 0.5 atm balloon filled with helium at stp is submerged under water where the pressure is 1.25 atm balloon filled with helium under water at 1.15 atm is released and floats to the surface, which is at stp volume increases volume decreases volume is unchanged

Explanation:

Step1: Recall Boyle's Law

$P_1V_1 = P_2V_2$ (constant $n$ and $T$), where $P$ is pressure and $V$ is volume. Volume is inversely - proportional to pressure.

Step2: Analyze "Balloon filled with helium at STP floats into air where the pressure equals 1 atm"

Since initial pressure at STP is 1 atm and new pressure is 1 atm, pressure is unchanged. So volume is unchanged.

Step3: Analyze "Balloon filled with helium at STP floats into the atmosphere where the pressure is 0.5 atm"

Initial pressure $P_1 = 1$ atm, new pressure $P_2=0.5$ atm. According to $P_1V_1 = P_2V_2$, when $P_2$ decreases, $V_2$ increases.

Step4: Analyze "Balloon filled with helium at STP is submerged under water where the pressure is 1.25 atm"

Initial pressure $P_1 = 1$ atm, new pressure $P_2 = 1.25$ atm. Since $P_2$ increases, according to $P_1V_1 = P_2V_2$, $V_2$ decreases.

Step5: Analyze "Balloon filled with helium under water at 1.15 atm is released and floats to the surface, which is at STP"

Initial pressure $P_1 = 1.15$ atm, new pressure $P_2 = 1$ atm. As $P_2$ decreases, according to $P_1V_1 = P_2V_2$, $V_2$ increases.

Answer:

Volume increases: Balloon filled with helium at STP floats into the atmosphere where the pressure is 0.5 atm; Balloon filled with helium under water at 1.15 atm is released and floats to the surface, which is at STP
Volume decreases: Balloon filled with helium at STP is submerged under water where the pressure is 1.25 atm
Volume is unchanged: Balloon filled with helium at STP floats into air where the pressure equals 1 atm