Question

learning goal: to understand several methods of measuring gas pressure. gases exert a measurable pressure (p) on the walls of their container. the si unit for pressure is the pascal (pa). other pressure units frequently used in chemistry are millimeters of mercury (mmhg) and atmospheres (atm). you can convert between units of pressure using conversion factors such as those indicated below: 1 atm = 760 mmhg = 101,325 pa. what is the pressure (in atmospheres) of the gas inside the container connected to an open - end, mercury - filled manometer as shown in the picture? (figure 1) the atmospheric pressure is 0.95 atm. express your answer numerically in atmospheres. view available hint(s) hint 1. how to approach this problem hint 2. convert the difference in mercury levels from centimeters to millimeters hint 3. convert the pressure difference to atmospheres gas pressure = atm submit previous answers request answer incorrect; try again; 3 attempts remaining provide feedback

Explanation:

Step1: Convert height difference to mmHg

The height difference of mercury is $18\ cm$. Since $1\ cmHg = 10\ mmHg$, then $18\ cmHg=18\times10 = 180\ mmHg$.

Step2: Convert mmHg to atm

We know that $1\ atm = 760\ mmHg$. So the pressure difference $\Delta P$ in atm is $\Delta P=\frac{180}{760}\ atm$.

Step3: Calculate gas pressure

The atmospheric pressure $P_{atm}=0.95\ atm$. The gas - pressure $P_{gas}$ is given by $P_{gas}=P_{atm}+\Delta P$.
$P_{gas}=0.95+\frac{180}{760}$
$P_{gas}=0.95 + 0.237$
$P_{gas}=1.187\ atm$

Answer:

$1.19$ (rounded to two decimal places)