Answer:
Then, at some point, these higher energy electrons give up their "extra" energy in the form of a photon of light, and fall back down to their original energy level.
Explanation:
When properly stimulated, electrons in these materials move from a lower level of energy up to a higher level of energy and occupy a different orbital.
Answer:
The number of moles of xenon are 1.69 mol.
Explanation:
Given data:
Number of moles of xenon = ?
Volume of gas = 37.8 L
Temperature = 273 K
Pressure = 1 atm
Solution:
The given problem will be solve by using general gas equation,
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
Now we will put the values in formula.
1 atm × 37.8 L = n × 0.0821 atm.L/ mol.K ×273 K
37.8 atm.L = n × 22.413 atm.L/ mol.
n = 37.8 atm.L / 22.413 atm.L/ mol.
n = 1.69 mol
The number of moles of xenon are 1.69.
Answer:
Explanation:
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In this case, since the equation we use to model the heat exchange into the calorimeter and compute the heat of reaction is:
We plug in the mass of water, temperature change and specific heat to obtain:
Now, this enthalpy of reaction corresponds to the combustion of propyne:
Whose enthalpy change involves the enthalpies of formation of propyne, carbon dioxide and water, considering that of propyne is the target:
However, the enthalpy of reaction should be expressed in kJ per moles of C3H4, so we divide by the appropriate moles in 7.00 g of this compound:
Now, we solve for the enthalpy of formation of C3H4 as shown below:
So we plug in to obtain (enthalpies of formation of CO2 and H2O are found on NIST data base):
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First we have to understand what a half life is. A half life is a measure of time when the amount of a certain object is 50% of the original amount. Hence the answer for this is letter A. The initial amount is 100. fifty percent of 100 is 50 and that happens after 15 hours. Hence, 15 hours is the half life period.
Answer:
P2= 125.26 Kpa
Explanation:
V1= 489.6 ml=0.4896L
V2= 750 ml= 0.750L
V1= 180 KPa= 180000 Pa
P2= ?
T1= 10 = 10 + 273.15 = 283.15K
T2= 28.7+273.15= 301.85K
180000Pa* 0.4896L/ 283.15K * 301.85K/0.75L
P2= 12526.28553
P2= 125.26 KPa
