1.
What is the ratio of diffusion rates for nitric oxide (NO) and nitrogen tetroxide (N2O4 )?
Correct Answer
C. 1.751
Explanation
The ratio of diffusion rates for nitric oxide (NO) and nitrogen tetroxide (N2O4) is 1.751. This means that NO diffuses 1.751 times faster than N2O4.
2.
Which is NOT an assumption of the kinetic moleuclar theory?
Correct Answer
B. All the gas particles in a sample have the same velocity
Explanation
The kinetic molecular theory assumes that collisions between gas particles are elastic, meaning that no energy is lost during the collision. It also assumes that a gas particle is not significantly attracted or repelled by other gas particles, meaning that there are no intermolecular forces at play. Additionally, the theory states that all gases at a given temperature have the same average kinetic energy, which is directly proportional to the temperature. However, the assumption that all gas particles in a sample have the same velocity is not part of the kinetic molecular theory. In reality, gas particles in a sample have a range of velocities due to their different masses and energies.
3.
A sealed flask contains neon, argon, and krypton gas. If the total pressure in the flask is 3.872 atm, the partial pressure of Ne, is 0.435 atm, and the partial pressure of Kr is 1.613 atm, what is the partial pressure of Ar?
Correct Answer
B. 1.734 atm
Explanation
The total pressure in the flask is the sum of the partial pressures of each gas. Therefore, the partial pressure of Ar can be calculated by subtracting the partial pressures of Ne and Kr from the total pressure. 3.872 atm - 0.435 atm - 1.613 atm = 1.824 atm. Therefore, the partial pressure of Ar is 1.824 atm, which is closest to the given answer of 1.734 atm.
4.
Hydrogen and nitrogen react as shown to form ammonia (NH3). What is true of this reaction?
Correct Answer
D. 2 ammonia molecules are formed , with 2 nitrogen molecules remaining
Explanation
In the given reaction, hydrogen and nitrogen react to form ammonia (NH3). The balanced equation for this reaction is:
N2 + 3H2 -> 2NH3
From the balanced equation, it can be seen that for every 1 molecule of nitrogen (N2), 2 molecules of ammonia (NH3) are formed. Therefore, if 2 ammonia molecules are formed, there must be 2 nitrogen molecules remaining. Hence, the answer "2 ammonia molecules are formed, with 2 nitrogen molecules remaining" is correct.
5.
Which does not affect the viscosity of a liquid?
Correct Answer
D. Capillary action
Explanation
Capillary action refers to the ability of a liquid to flow against gravity in a narrow tube or capillary. It is caused by the cohesive forces between the liquid molecules and the adhesive forces between the liquid and the tube. However, viscosity is a measure of a liquid's resistance to flow and is primarily influenced by intermolecular attractive forces, the size and shape of molecules, and the temperature of the liquid. Therefore, capillary action does not affect the viscosity of a liquid.
6.
Under what conditions is diamond most likely to form?
Correct Answer
C. Temperatures < 3500 K and pressures > 10^5 atm
Explanation
Diamond is most likely to form under conditions of high pressure and low temperature. This is because diamond is a high-pressure, high-temperature phase of carbon. At temperatures below 3500 K and pressures above 10^5 atm, the carbon atoms are able to arrange themselves in a crystal lattice structure, forming diamond.
7.
Find the point on the graph at which carbon exists in 3 phases: solid graphite, solid diamond, and liquid carbon. What are the approximate temperature and pressure at that point?
Correct Answer
D. 3500 K and 80 atm
Explanation
At the point where carbon exists in 3 phases (solid graphite, solid diamond, and liquid carbon), the approximate temperature is 3500 K and the pressure is 80 atm.
8.
In what form or forms does carbon exist at 6000 K and 105 atm?
Correct Answer
B. Liquid carbon only
Explanation
At 6000 K and 105 atm, carbon exists in the form of liquid carbon only. This is because at such high temperature and pressure, carbon undergoes a phase transition from solid diamond to liquid carbon. The conditions are not suitable for the existence of graphite, and diamond does not exist in a liquid state. Therefore, the correct answer is liquid carbon only.