Gas laws
The ideal gas equation
More chapter 5 questions
Chapter 6
100
How many mmHg are in 1 atm? How many pascals (Pa) are in 1 atm? How many pascals (Pa) are in 1 kilopascal (kPa)? Convert 295 mmHg to kilopascals using dimensional analysis and please show ALL units!
1 atm = 760 mmHg, 1 atm = 101,325 Pa or 1.01325 x 10^5 Pa, 1 kPa = 1000 Pa, 39.3 kPa
100
What is the ideal gas equation and what do each letter stand for?
PV = nRT Where P is the pressure of the gas, V is the volume of the gas, n is the number of moles, R is the gas constant (0.0821 L*atm/K*mol), T is the temperature (in kelvins)
100
What is the density (in g/L) of uranium hexafluoride (UF6) at 779 mmHg and 62 C?
d = PM/RT where P is the pressure, M is the molar mass, R is the gas constant, and T is the temperature in K.
100
What is energy?
Capacity to do work
200
What is Boyle's law and what is the relationship between pressure and volume?
Boyle's law states that the pressure of a fixed amount of gas at a constant temperature is INVERSELY proportional to the volume of the gas. This means that as the pressure (P) is increased at constant temperature, the volume (V) occupied by a given amount of gas decreases.
200
What does STP stand for? How many liters does 1 mole of an ideal gas occupy at STP?
STP stands for standard temperature and pressure which are 273.15 K (or 0 C) and 1 atm. 1 mole of an ideal gas occupies 22.41 L at STP.
200
The equation for the metabolic breakdown of glucose (C6H12O6) is the same as the equation for the combustion of glucose in air: C6H12O6(s) + 6O2(g) --> 6CO2(g) + 6H2O(l) Calculate the volume of CO2 produced at 37 C and 1.00 atm when 5.60 g of glucose is used up in the reaction.
4.75 L
200
An iron bar of mass 869 g cools from 94 C to 5 C. Calculate the heat released (in kilojoules) by the metal.
q= ms(deltaT) q is the amount of heat that has been absorbed or released in a particular process, m is the mass of the substance in grams, s is the specific heat, and deltaT is the change in temperature (Tf-Ti). The specific heat (s) of a substance is the amount of heat required to raise the temperature of one gram of the substance by one degree Celcius. -34.3 kJ Because heat is released by the metal to the surroundings, it has a negative sign.
300
What is Charles's and Gay-Lussac's law? And what is the relationship between the temperature and volume of the gas?
It states that the volume of a fixed amount of gas maintained at constant pressure is DIRECTLY proportional to the absolute temperature of the gas. This means that as the temperature (T) increases at constant pressure, the volume occupied by a given amount of gas increases as well.
300
Calculate the volume of 5.69 g of NH3 gas trapped in a container at a pressure of 3.00 atm and a temperature of 41.0 C.
PV = nRT Solve for V: V= nRT/P V = 2.87 L
300
Calculate the partial pressure of oxygen and hydrogen in a mixture of 35. 0 g of oxygen gas and 11.5 g of hydrogen gas in a 2.0 L container at 275 K.
partial pressure of oxygen (Po) = mole fraction of oxygen (Xo) times the total pressure (Pt) partial pressure of hydrogen (Ph) = mole fraction of hydrogen (Xh) times the total pressure (Pt). Partial pressure for oxygen = 1.968 atm and the partial pressure for hydrogen = 54.012 atm
300
A quantity of 1.922 g of methanol (CH3OH) was burned in a constant-volume bomb calorimeter. Consequently, the temperature of the water rose by 4.20 C. If the heat capacity of the bomb plus water was 10.4 kJ/C, calculate the molar heat of combustion of methanol
The heat absorbed by the bomb and water is equal to the product of the heat capacity and the temperature change. So we use this equation: qcal=Ccal(deltaT) = (10.4 kJ/C)(4.20 C) = 43.68 kJ because qcal=-qrxn, the heat change of the reaction is -43.68 kJ. This is the heat released by the combustion of 1.922 g of CH3OH, therefore we can write the conversion factor as: -43.68 kJ/1.922 g. The molar mass of methanol is 32.04 g/mol. = -728 kJ/mol
400
What is Avogrado's law and the volume-amount relationship?
Avogrado's law states that at constant pressure and temperature, the volume of a gas is DIRECTLY proportional to the number of moles of the gas present. This means that as you add more gas molecules, the volume will increase and as you remove gas, the volume will decrease.
400
Calculate the concentration of CO2 gas trapped in a 3.0 L container at a pressure of 2.8 atm and at a temperature of 80 C.
0.097 M
400
Calculate the root-mean square speed of molecular chlorine in m/s at 20 C
use Urms = square root of 3RT/M 1 J = 1 kgm^2/s^2 321 m/s
400
A 30.14-g stainless steel ball bearing at 117.82 C is placed in a constant-pressure calorimeter containing 120.0 mL of water at 18.44 C. If the specific heat of the ball bearing is 0.474 J/g*C. Calculate the final temperature of the water. Assume the calorimeter to have negligible heat capacity.
21.19 C
500
What is absolute zero in Kelvin and Celcius scale? What is the freezing point of water in Kelvin and celcius scale? What is the boiling point of water in Kelvin and Celcius scale?
Absolute zero = 0 K and -273.15 C, Freezing point of water = 273.15 K and 0 C, Boiling point of water = 373.15 K and 100 C
500
how many liters of oxygen at STP are needed to burn 3.0 L of octane?
37.5 L
500
It takes 192 seconds for an unknown gas to effuse through a porous wall and 84 seconds for the same volume of nitrogen gas to effuse at the same temperature and pressure. What is the molar mass of the unknown gas?
146 g/mol
500
A quantity of 100 mL of 0.500 M HCl was mixed with 1.00 x 10^2 mL of 0.500 M NaOH in a constant-pressure calorimeter of negligible heat capacity. The initial temperature of the HCl and NaOH solutions was the same, 22.50 C, and the final temperature of the mixed solution was 25.86 C. Calculate the heat change for the neutralization reaction on a molar basis NaOH(aq) + HCl(aq) --> NaCl(aq) + H2O(l) assume that the densities and specific heats of the solutions are the same as for water (1.00 g/mL and 4.184 J/g*C)
Assuming no heat is lost to the surroundings, qsys = qsoln + qrxn = 0 so qrxn = -qsoln is the heat absorbed by the combined solution. Because the density of the solution is 1.00 g/mL, the mass of a 100 mL solution is 100 g. qsoln = msdT = (100 g + 100 g)(4.184 J/g*C)(25.86 C-22.50 C) = 2.81 x 10^3 J = 2.81 kJ. Because qrxn = -qsoln, qrxn = -2.81 kJ. From the molarities given, the number of moles of both HCl and NaOH in 100 mL solution is 0.500 mol/1L x 0.100 L = 0.0500 mol. Therefore the heat of neutralization when 1.00 mole of HCl reacts with 1.00 mole of NaOH is: heat of neutralization = -2.81 kJ/0.0500 mol = -56.2 kJ/mol
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