Answer:
![P_(H_2)=727mmHg](https://img.qammunity.org/2022/formulas/chemistry/college/aaglc6esli7psaqt26lo08polynjhtixho.png)
Step-by-step explanation:
Hello there!
In this case, according to the given data, it is possible to infer that the gas mixture lies on the 15.0 cm-high column of water, so that the total pressure or atmospheric pressure is given by:
![P_(atm)=P_(water)+P_(H_2)](https://img.qammunity.org/2022/formulas/chemistry/college/tzt4sih9n078iup2hma5uq3r7sqc9858rv.png)
Thus, since the atmospheric pressure is 745 mmHg and the vapor pressure of water is 18 mmHg, the pressure of hydrogen turns out to be:
![P_(H_2)=P_(atm)-P_(water)\\\\P_(H_2)=745mmHg-18mmHg\\\\P_(H_2)=727mmHg](https://img.qammunity.org/2022/formulas/chemistry/college/90ewpuhl1einy6iq2fcdut34h1kemvck9j.png)
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