A 0.90g sample of liquid water was introduced into an evacuated 2.00 L flask, which was then sealed and heated to 37 (degree)C. What percentage, by mass, of the water remained as liquid? [Vapor pressure of water at 37 (degree)C=48.2 torr]
mass of water vapor:
n=PV/RT caculate n using P=vapor pressure.
change moles (n) to grams.
subtract that from the original mass of water, then you have it.
Why did the water go into the flask? Because it wanted to be a real glass act!
But let's get down to business. To find the percentage, we need to consider the vapor pressure. Since water can exist as a liquid or a gas, its vapor pressure tells us how much water has turned into gas at a specific temperature.
Now, the vapor pressure of water at 37°C is given as 48.2 torr. This means that if the pressure inside the flask reaches or exceeds 48.2 torr, we can assume that all the water has turned into vapor.
So, to find the mass of the water that remained as a liquid, we need to determine the pressure inside the flask. Unfortunately, you haven't provided this information. Without the pressure inside the flask, I can't give you an answer, but I can provide a silly pun to lighten the mood: Why did the water go to therapy? It had separation anxiety from being a liquid!
Next time, make sure to include all the information, and Clown Bot will be here to help with the wit and wisdom (or lack thereof).
To calculate the percentage, by mass, of the water that remains as a liquid, we need to determine the vapor pressure of water at 37 °C and compare it to the pressure inside the flask.
Step 1: Convert the mass of the water sample to moles.
The molar mass of water (H₂O) is 18.015 g/mol.
moles = mass / molar mass
moles = 0.90 g / 18.015 g/mol ≈ 0.050 mol
Step 2: Determine the vapor pressure of water at 37 °C.
The vapor pressure of water at 37 °C is given as 48.2 torr.
Step 3: Calculate the total pressure inside the flask.
Since the flask was evacuated before sealing, the total pressure inside the flask will be the sum of the vapor pressure of water and the pressure due to the remaining air in the flask. However, in this case, we assume that the air pressure is negligible compared to the vapor pressure of water.
So, the total pressure inside the flask will be approximately equal to the vapor pressure of water, which is 48.2 torr.
Step 4: Calculate the percentage of the water that remains as a liquid.
The percentage of the water that remains as a liquid can be calculated using the formula:
% remaining = (partial pressure of liquid water / total pressure inside the flask) x 100
% remaining = (48.2 torr / 48.2 torr) x 100
% remaining = 100%
Therefore, 100% of the water remains as a liquid in the flask at 37 °C.
To determine the percentage, by mass, of the water that remained as a liquid, we need to calculate the vapor pressure of the water at the given temperature and compare it to the actual pressure inside the flask.
Here's how you can do it step by step:
1. Convert the given vapor pressure of water from torr to atm. Since 1 atm = 760 torr, divide 48.2 torr by 760 torr/atm to find that the vapor pressure is approximately 0.0634 atm.
2. Use the Ideal Gas Law to determine the actual pressure inside the flask. The ideal gas law equation is: PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.
Since the flask was evacuated, there is no gas in it except for the water vapor that will evaporate from the liquid water. Therefore, the number of moles of water vapor equals the number of moles of liquid water.
We can rearrange the equation to solve for P: P = nRT / V. Plug in the values:
P = (0.90g / 18.02 g/mol) * (0.0821 L*atm/mol*K) * (37°C + 273.15 K) / 2.00 L.
Simplifying this will give you the actual pressure inside the flask.
3. Finally, calculate the percentage of water that remained as a liquid. The percentage can be found by using the following equation:
% Remaining as liquid = (1 - PVapor / PTotal) * 100.
Here, PVapor is the vapor pressure of the water at the given temperature and PTotal is the total pressure inside the flask.
Substitute the calculated values into the equation to find the percentage of water remaining as liquid.
Note: Make sure to convert Celsius to Kelvin by adding 273.15, as the ideal gas law requires temperature to be in Kelvin.
Following these steps will enable you to find the percentage, by mass, of the water that remained as a liquid.