Pure Substances and Mixtures
Separating Mixtures
Inter/Intra-molecular Forces
Gas Laws Review
Dalton's Law
100
Which diagram represents a compound?
100
The filtration process is shown below. What particles will be collected in the beaker?
The blue particles will be collected in the beaker. The brown particles are too big to pass through the filter paper.
100
Intermolecular or Intramolecular?
The forces that hold atoms together within a molecule
Intramolecular
100
100 degrees Celsius to Kelvin?
373.15 K
100
A container holds two gases: Gas A (2.0 atm) and Gas B (1.5 atm). What is the total pressure?
3.5 atm
200
Three atoms of three different elements, He, Ne, and Ar, are shown below. What element do you expect Element #2 to be?
Argon
200
Based on the effusion separation process below, which particle (green or purple) would have a greater mass?
Purple
200
Intermolecular or Intramolecular?
The stronger force
Intramolecular
200
A gas has a pressure of 2.0 atm in a 3.0 L container. If the pressure increases to 6.0 atm, what is the new volume?
1.0 L
200
A mixture contains hydrogen, nitrogen, and oxygen. Their partial pressures are 0.4 atm, 0.6 atm, and 0.5 atm, respectively. What fraction of the total pressure is due to oxygen?
Xoxygen = 0.33
300
Is a glass of milk considered a pure substance?
No, homogeneous mixture
300
Based on the chromatogram, which substances make up the Unknown sample?
Unknown sample is a mixture of A, B, and C.
300
Intermolecular or Intramolecular?
Intramolecular
300
A 3.0 L sample of gas is cooled from 350 K to 175 K. What is the new volume?
1.5 L
300
A container holds a gas mixture with a total pressure of 3.0 atm. The partial pressure of nitrogen is 1.2 atm, and oxygen is 0.8 atm. What is the partial pressure of argon?
PAr = 1.0 atm
400
An element made of two identical atoms has a molecular mass of 32amu. Draw the element. What is the element?
Oxygen
400
A very nonpolar solvent is used as the mobile phase for the chromatography experiment below. What color substance is the most attracted to the solvent? Is this color polar or nonpolar?
Purple, nonpolar
400
Which substance would has the strongest intermolecular forces?
Ammonia
400
The pressure in an aerosol can is 2.0 atm at 25°C. If it is left in the sun and reaches 75°C, what will the new pressure be?
2.33 atm
400
A container has nitrogen at 300 K with a partial pressure of 0.9 atm. Oxygen in the same container has a partial pressure of 0.7 atm. If the temperature rises to 600 K, what is the total pressure assuming volume is constant?
Total pressure is 3.2 atm
500
Is water an element? Explain your answer.
Water is NOT an element, it is a compound. An element is a pure substance made of only one type of atom.
500
Which substance would have stronger intermolecular forces?
Substance B
500
Why do nonpolar substances generally have lower boiling points than polar substances?
Nonpolar substances have weaker intermolecular forces. Polar substances have uneven distributions of charge within their molecules, so one end is slightly positive and the other end is slightly negative. The uneven distribution of charge can attract oppositely charged molecule ends to create greater forces of attraction.
500
Why must temperature be measured in Kelvin for gas law calculations?
Kelvin is an absolute temperature scale where 0 K represents absolute zero, the point at which all molecular motion stops. Temperature must be measured in Kelvin for gas law calculations because gas laws (Boyle’s, Charles’s, Gay-Lussac’s, and the Combined Gas Law) rely on a proportional relationship between temperature and volume or pressure.
500
A container contains 57 particles of a gas mixture. What is the total pressure of the container if 12% of the gas mixture has a partial pressure of 1.2 atm?
Total pressure is 10 atm