Pdil 2018 b) T/F Consider the reaction N2+3H2 2NHa. A mixture of 1 mol each of nitrogen and hydrogen gases under the same conditions in a container fitted with a piston. The ratio of volumes of the container (Vfina./Viniris) is ภ331 c) T/FA 4.01 g of sample of a certain diatomic gas occupies a volume of 3.73-L at 1.00 atm and a temperature of 45°C. The gas may be N2 d) T/F state properties. Among pressure, temperature internal energy, enthalpy, work and, heat, 4 of them are e) T/F For the following process which is done constant P and T (P - 1 atm and T 370 K) H20(g) >H2O(U) heat and work are both negative. T/F (1) When solid KBr is dissolved in water, the solution gets colder (2) When concentrated f) Two of the following processes are exothermic: H-S0A is added to water. the solution gets verv high. (3) Water is boiling in a tea kettle T/FIn a process in which one mole of a gas is expanded from state A to state B, the final volum of the gas will not depend on the path taken g) h) T/F The change in enthalpy can always be thought of as equal to energy flow as heat. i) T/F A gamma ray of wavelength 1.00 x 10 cm has enough energy to remove an electron fre a hydrogen atom. T/F The magnetic quantum number is related to the orientation of the orbital in space relat to the other orbitals in the atom. j)
Show transcribed image textPdil 2018 b) T/F Consider the reaction N2+3H2 2NHa. A mixture of 1 mol each of nitrogen and hydrogen gases under the same conditions in a container fitted with a piston. The ratio of volumes of the container (Vfina./Viniris) is ภ331 c) T/FA 4.01 g of sample of a certain diatomic gas occupies a volume of 3.73-L at 1.00 atm and a temperature of 45°C. The gas may be N2 d) T/F state properties. Among pressure, temperature internal energy, enthalpy, work and, heat, 4 of them are e) T/F For the following process which is done constant P and T (P - 1 atm and T 370 K) H20(g) >H2O(U) heat and work are both negative. T/F (1) When solid KBr is dissolved in water, the solution gets colder (2) When concentrated f) Two of the following processes are exothermic: H-S0A is added to water. the solution gets verv high. (3) Water is boiling in a tea kettle T/FIn a process in which one mole of a gas is expanded from state A to state B, the final volum of the gas will not depend on the path taken g) h) T/F The change in enthalpy can always be thought of as equal to energy flow as heat. i) T/F A gamma ray of wavelength 1.00 x 10 cm has enough energy to remove an electron fre a hydrogen atom. T/F The magnetic quantum number is related to the orientation of the orbital in space relat to the other orbitals in the atom. j)
Consider a container with a frictionless piston that contains a given amount of an ideal gas. If the external pressure is kept constant, the piston will move up or down in response to a change in the internal pressure. The piston will move up if Pint > Pext and vice versa. The piston will stop moving when Pint = Pext (the system is equilibrated).
The following problem will slowly guide you through a work calculation. Some questions may appear trivial, so trust your instincts and donât assume there are hidden tricks. The goal of such a guided exercise is to help you picture the situation so you understand how all relevant variables change or stay the same. This is the first in a sequence of related problems.
Remember to use three significant figures for all numerical answers. The margin of error for each numerical answer is 5%. To avoid rounding errors use the unrounded intermediate values in your final calculations.
Letâs assume the initial volume of the gas is 3.90 L , the initial temperature of the gas is 26.0 °C , and the system is in equilibrium with an external pressure of 1.2 bar (given by the sum of a 1 bar atmospheric pressure and a 0.2 bar pressure due to a brick that rests on top of the piston).
Part A
How many moles of gas are there in the container?
n =
mol
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You now heat the gas slowly until the temperature reaches 51.2 °C You do it slowly so the piston can move if necessary until a new equilibrium is reached.
Part B
What happens with the piston while you heat the gas?
What happens with the piston while you heat the gas?
It moves up
It stays in the same position
It moves down
When the final temperature is reached, you stop heating the gas.
Part C
What is the final pressure of the gas?
P =
bar
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Part D
What is the final volume of the gas?
V =
L
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Part E
What happens with the piston after you finish heating the gas? Assume you do not need to worry about the gas cooling down again because the outside of the container is at a lower temperature. That is, you manage to keep the gas at a constant temperature that equals 51.2 °C
What happens with the piston after you finish heating the gas? Assume you do not need to worry about the gas cooling down again because the outside of the container is at a lower temperature. That is, you manage to keep the gas at a constant temperature that equals 51.2
It moves down
It moves up
It stays in the same position
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So far this was all at the level of your general chemistry class. Letâs now calculate the work involved in the process. Recall the sign conventions we use in physical chemistry, and always think from the point of view of the system (the gas).
Part F
What is the sign of w?
What is the sign of w?
negative
positive
zero
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Part G
What is the value of w? Be careful with units. How do you convert bar*L to J?