Analyze and Evaluate Scientific Explanations and Predictions Practice Test

A sealed syringe contains 10.0 mL of an ideal gas at 1.0 atm and 300 K. The plunger is pushed quickly to 5.0 mL, and the process is approximated as adiabatic. The student repeats the compression slowly and approximates it as isothermal. Which prediction is most consistent with thermodynamic principles for the final pressure in the fast (adiabatic) compression compared with the slow (isothermal) compression to the same final volume?

A researcher tests whether dissolved CO$_2$ (aq) measurably acidifies water in a sealed 1.0 L vessel at 25°C. The vessel initially contains pure water equilibrated with 1.0 atm N$_2$ (no CO$_2$). The headspace gas is then replaced with 0.20 atm CO$_2$ (balance N$_2$) and allowed to re-equilibrate without changing temperature. Assume Henry’s law for CO$_2$: $\text{CO}2(\text{aq})=k_H P{\text{CO}_2}$ with $k_H=3.3\times10^{-2}$ M/atm, and that each dissolved CO$_2$ molecule contributes at most one H$^+$ via $\text{CO}_2+\text{H}_2\text{O}\rightleftharpoons \text{H}^+ + \text{HCO}_3^-$. Which prediction is most consistent with these principles regarding the final pH compared with the initial pH (7.0)?