Gas Laws Pressure Temperature Volume Moles
Calculate the number of moles of H2 in 11L of gas at STP. Your answer should have two significant figures.
1mol of gas occupies a volume of about 22.4L at STP, so the number of moles in 11L can be found by multiplying by a conversion factor. 11L×1mol22.4L=0.4911mol The answer should have two significant figures, so round to 0.49mol.
If a balloon at 25∘C with 2.3 L of volume is expanded to 40.0 L, what will the new Celsius temperature be? Select the correct answer below: 4,900∘C 5,100∘C 5,500∘C 4,200∘C
4,900∘C According to Charles's law, we have V1T1=V2T2. First convert the given temperature from Celsius to Kelvin, because any problem involving products or quotients of a temperature must use a temperature scale in which absolute zero has a numerical value 0 (or, in other words, cannot have negative temperatures). The SI unit of Kelvin meets this criterion. 25∘C+273.15 K=298.15 K Substitute in the given values and solve. (2.3 L298.15 K)=(40.0 LT2)T2=5,185.2 K Now that we have the final temperature in Kelvin, convert the temperature back to Celsius since that is the unit requested in the question. 5,185.2 K−273.15 K=4,912.05∘C Since the original volume had two significant figures, this value is only precise to the hundreds place. Rounding the temperature to the hundreds place gives 4,900∘C.
Which of the following states that the pressure of a given amount of gas is directly proportional to its temperature on the Kelvin scale when the volume is held constant? Amontons's or Gay-Lussac's law Charles's law Boyle's law Hess's law
Amontons's or Gay-Lussac's law Amontons's or Gay-Lussac's law states that the pressure of a given amount of gas is directly proportional to its temperature on the Kelvin scale when the volume is held constant. This can be seen in P1T1=P2T2. As the temperature of a gas increases by a certain factor, the gas pressure will also increase by the same factor. And if the temperature of a gas decreases by a certain factor, the gas pressure will also decrease by the same factor.
How many molecules of hydrogen are in 67.2L of H2 at STP? Use NA=6.022×1023mol−1 for Avogadro's number. Your answer should have three significant figures. (Round to two decimal places in scientific notation.)
One mole of a gas at STP has a volume of 22.4L. First determine the number of moles of gas you have 67.2L22.4L/mol=3.0000moles. One mole of a substance contains Avogadro's number of particles, or 6.022×1023molecules in the case of a molecular gas.So multiply the number of moles by the number of molecules per mole: 3.0000mol×6.022×1023moleculesmol=1.8066×1024molecules The answer should have three significant figures, so round to 1.81×1024.
How many atoms of helium are in 53.1L of He at STP? Use NA=6.022×1023mol−1 for Avogadro's number. Your answer should have three significant figures. Report your answer using scientific notation.
One mole of any gas at STP has a volume of 22.4L. So first determine the number of moles of gas you have 53.1L22.4L/mol=2.370mol One mole of a substance contains Avogadro's number of particles, or 6.022×1023atoms for a monoatomic gas like helium. Multiply the number of moles by the number of atoms per mole: 2.370mol×6.022×1023atomsmol=1.427×1024atoms The answer has three significant figures, so round to 1.43×10^24atoms.
A 650 mL sample of neon gas exerts a pressure of 0.125 atm. If compressed until the pressure is 0.600 atm, what will be the final volume of the sample in milliliters?
Recall that the relationship between the pressure and volume of a fixed quantity of gas at a constant temperature is known as Boyle's law: P1V1=P2V2. First, rearrange the equation to solve for V2. V2=P1V1P2 Next, substitute in the known values and solve. V2=(0.125 atm)(650 mL)0.600 atm=135.417 mL The answer should have three significant figures, so round to 135 mL.
A sample of CO2 occupies 1.5 L at 250 K. What will the volume be at 450 K in liters? Your answer should have two significant figures (round your answer to one decimal place). Do not include units in your response. Provide your answer below:
Recall that the relationship between the volume and temperature of a fixed quantity of gas at constant pressure is given by Charles's law: V1T1=V2T2. First, rearrange the equation to solve for V2. V2=V1T2T1 Next, substitute in the known values and solve. V2=(1.5 L)(450 K)250 K=2.7 L The answer should have two significant figures, so keep the answer as 2.7 L.
Under conditions of constant temperature and amount of substance, a plot of pressure vs. volume for an ideal gas will result in __________. Select the correct answer below: a line a parabola a logarithmic function none of the above
This plot will give a hyperbolic relationship because there is an inverse relationship between the pressure and the volume of an ideal gas under conditions of constant temperature and constant amount of substance (constant number of moles, n).
A large flexible balloon contains 1.5moles of a gas in a volume of 27liters. If 1.1moles of the gas are removed and the pressure and temperature do not change, what will be the new volume of the gas? Round to two significant figures.
Use the equation V1n1=V2n2. Let V1=27L, n1=1.5mol, and n2=(1.5−1.1)mol=0.4mol. Rearrange the equation and solve for the number of liters, V2, that corresponds to the reduced number of moles. V1n1V1n2n1=V2n2=V2 Substitute and simplify. (27L)(0.4mol)1.5mol=7.2L
Which plot will give a straight line? Select the correct answer below: V vs. P V vs. 1P 1V vs. 1P V vs. ln(P)
V vs. 1P Volume and pressure are inversely related, so only the reciprocal of the pressure against volume results in a linear plot.
What is the molar mass of a gas if 1.15g of the gas has a volume of 224mL at STP?Your answer should have three significant figures. (Round to the nearest whole number.)
What is the molar mass of a gas if 1.15g of the gas has a volume of 224mL at STP?Your answer should have three significant figures. (Round to the nearest whole number.)
Which is a correct way of stating Boyle's law? Select the correct answer below: P=k×1V, where k is a constant. PV=k, where k is a constant. P1V1=P2V2, where the indices 1 and 2 corresponds to different states of the same gas sample. all of the above
all of the above Boyle's law states that the volume and pressure of a gas vary inversely if the gas is held at a constant temperature. In other words, if the volume is increased by a certain factor, the pressure will decrease by same factor. All three of these equations are ways of expressing this concept mathematically.
Which is a correct way of stating Charles's law? Select the correct answer below: V=kT VT=k V1T1=V2T2 all of the above
all of the above These are all valid ways of expressing Charles's law.
If the pressure of a gas is kept constant and the temperature (in Kelvin) is cut in half, the volume will __________. double quadruple be cut in half be cut in one fourth
be cut in half Since volume and temperature are directly proportional, if one is cut in half, the other must also be halved.
Pressure and temperature are __________ proportional on the Kelvin scale. inversely semi not directly
directly On the Kelvin scale, pressure and temperature are directly proportional. Amontons's law states that the pressure of a given amount of gas is directly proportional to its temperature on the Kelvin scale when the volume is held constant. This can be seen in P1T1=P2T2. As the temperature of a gas increases by a certain factor, the gas pressure will also increase by the same factor. And if the temperature of a gas decreases by a certain factor, the gas pressure will also decrease by the same factor.
Pressure and temperature of an ideal gas are __________. Select the correct answer below: directly proportional inversely proportional identical depends on the gas
directly proportional As temperature increases or decreases, the pressure will increase or decrease accordingly, if the volume is kept constant.
Gay-Lussac's law assumes that __________. (Select all the are true.) Select all that apply: the temperature is held constant the volume is held constant the number of moles is held constant the force is held constant
the volume is held constant the number of moles is held constant According to Gay-Lussac's law, the pressure and temperature of a gas (in degrees Kelvin) are directly proportional. If one increases, the other one will increase as well (and the same for decrease). This relationship is valid as long as the volume and number of moles of gas are held constant.
