A. When the substance is in its gaseous state.
<u>Explanation:</u>
When a substance is expanding against its constant volume and pressure, its temperature increases except when the substance is in gaseous state and not in liquid or solid state. So the internal energy increase in the system not only increases and maintaining the volume and pressure of the system remains constant in its gaseous phase. In the first law of Thermodynamics, it is used specifically that to especially in the case of gaseous system.
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Characteristic properties can be used to describe and identify the substances, while non-characteristic properties, although can be used to describe the substances, cannot be used to identify them.
Temperature, mass, color, shape and volume are examples of non-characteristic properties.
Density, boiling point, melting point, chemical reactivity are examples of characteristic properties.
List of the properties observed by the scientist:
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Property Type of property
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Volume: 5 ml non-characteristic
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Color: blue non-characteristic
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State: liquid characteristic
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density: 1.2 g/cm characteristic
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Reaction: reacts with CO2 characteristic
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Answer:
moles B = 2.32 moles
Explanation:
In this case, we can assume that both gases are ideals, so we can use the expression for an ideal gas which is:
PV = nRT
From here, we can calculate the total moles (n) that are in the container, and then, by difference, we can calculate how much we have of gas B.
For this case, we will use R = 0.082 L atm / mol K. Solving for n:
n = PV/RT
n = 5 * 20 / 0.082 * 303
n = 4.02 moles
If we have 4.02 moles between the two gases, and we have 1.70 from gas A, then from gas B we simply have:
Total moles = moles A + moles B
moles B = Total moles - moles A
moles B = 4.02 - 1.70
moles B = 2.32 moles
We have 2.32 moles of gas B
The answer is D glad to help :)<span />
