- What is the pressure in atm, mmHg, torr, kPa at standard temperature and pressure? (1 point)
- What is the temperature in °C and K at standard temperature and pressure? (1 point)
- If atmospheric pressure today is 0.914 atm, what is it in mmHg? (2 points)
- Is the pressure in question 9 above or below atmospheric pressure? Justify your answer being sure to include a discussion of what atmospheric pressure might be. (2 points)
- How many grams of oxygen gas are in a 21.3 L container at a pressure of 0.9186 atm and a temperature of 18.3°C? (3 points)
The Correct Answer and Explanation is :
Let’s address each question in turn:
7. What is the pressure in atm, mmHg, torr, kPa at standard temperature and pressure?
tandard Temperature and Pressure (STP) is commonly defined as a temperature of 0°C (273.15 K) and a pressure of 1 atmosphere (atm).t this standard pressure:
- Atmospheres (atm): atm- Millimeters of mercury (mmHg): 60 mmHg- Torr: 60 torr (since 1 torr = 1 mmHg)- Kilopascals (kPa): 01.325 kPa
hese values are widely accepted in scientific contexts.citeturn0search19
8. What is the temperature in °C and K at standard temperature and pressure?
t STP, the standard temperature is:
- Degrees Celsius (°C): °C- Kelvin (K): 73.15 K
he Kelvin scale is an absolute temperature scale starting at absolute zero, and the conversion from Celsius to Kelvin is achieved by adding 273.15 to the Celsius temperature.
9. If atmospheric pressure today is 0.914 atm, what is it in mmHg?
o convert atmospheric pressure from atmospheres to millimeters of mercury (mmHg), use the conversion factor:
atm = 760 mmHg
herefore:
.914 atm × 760 mmHg/atm = 694.64 mmHg
o, an atmospheric pressure of 0.914 atm is equivalent to 694.64 mmHg.
10. Is the pressure in question 9 above or below atmospheric pressure? Justify your answer being sure to include a discussion of what atmospheric pressure might be.
he pressure of 0.914 atm (or 694.64 mmHg) is below the standard atmospheric pressure of 1 atm (760 mmHg).tmospheric pressure is the force exerted onto a surface by the weight of the air above that surface in the Earth’s atmosphere.t sea level, standard atmospheric pressure is defined as 1 atm.ariations in atmospheric pressure occur due to changes in altitude, weather patterns, and temperature.ower atmospheric pressure can be observed at higher elevations or during certain weather conditions, such as the approach of a storm system.n this case, a reading of 0.914 atm indicates a lower-than-average atmospheric pressure, which could be due to such factors.
11. How many grams of oxygen gas are in a 21.3 L container at a pressure of 0.9186 atm and a temperature of 18.3°C?
o determine the mass of oxygen gas under the given conditions, we can use the Ideal Gas Law:
V = nRT
Where:
- = pressure (in atm)- = volume (in liters)- = number of moles of gas- = ideal gas constant (0.0821 L·atm·K⁻¹·mol⁻¹)- = temperature (in Kelvin)
First, convert the temperature to Kelvin:
(K) = 18.3°C + 273.15 = 291.45 K
Next, solve for the number of moles (n):
= PV / RT
= (0.9186 atm) × (21.3 L) / (0.0821 L·atm·K⁻¹·mol⁻¹ × 291.45 K)
≈ 0.9186 × 21.3 / (0.0821 × 291.45)
≈ 19.56318 / 23.926845
≈ 0.817 moles
he molar mass of oxygen gas (O₂) is approximately 32.00 g/mol.herefore, the mass (m) is:
= n × molar mass
= 0.817 moles × 32.00 g/mol
≈ 26.14 grams
hus, the container holds approximately 26.14 grams of oxygen gas under the specified conditions.
Explanation:
he Ideal Gas Law (PV = nRT) is a fundamental equation in chemistry that relates the pressure, volume, temperature, and amount of an ideal gas.n this problem, we are given the pressure (P = 0.9186 atm), volume (V = 21.3 L), and temperature (T = 18.3°C), and we aim to find the mass of oxygen gas present.
irst, it’s essential to convert the temperature from Celsius to Kelvin, as the Ideal Gas Law requires absolute temperature.dding 273.15 to the Celsius temperature gives us 291.45 K.
ext, we rearrange the Ideal Gas Law to solve for the number of moles (n):
= PV / RT
y substituting the known values into this equation, we calculate the number of moles of oxygen gas.nce we have the number of moles, we can determine the mass by multiplying by the molar mass of oxygen gas (O₂), which is 32.00 g/mol.
his approach assumes that oxygen behaves as an ideal gas under the given conditions.hile real gases exhibit slight deviations from ideal behavior, especially under extreme temperatures or