If an atom suffers from a collision, that causes an electron to jump from a lower to higher state, it is called collisional excitation
Answer:
3853 g
Step-by-step explanation:
M_r: 107.87
16Ag + S₈ ⟶ 8Ag₂S; ΔH°f = -31.8 kJ·mol⁻¹
1. Calculate the moles of Ag₂S
Moles of Ag₂S = 567.9 kJ × 1 mol Ag₂S/31.8kJ = 17.858 mol Ag₂S
2. Calculate the moles of Ag
Moles of Ag = 17.86 mol Ag₂S × (16 mol Ag/8 mol Ag₂S) = 35.717 mol Ag
3. Calculate the mass of Ag
Mass of g = 35.717 mol Ag × (107.87 g Ag/1 mol Ag) = 3853 g Ag
You must react 3853 g of Ag to produce 567.9 kJ of heat
Answer : The mole fraction and partial pressure of
and
gases are, 0.267, 0.179, 0.554 and 1.54, 1.03 and 3.20 atm respectively.
Explanation : Given,
Moles of
= 1.79 mole
Moles of
= 1.20 mole
Moles of
= 3.71 mole
Now we have to calculate the mole fraction of
and
gases.


and,


and,


Thus, the mole fraction of
and
gases are, 0.267, 0.179 and 0.554 respectively.
Now we have to calculate the partial pressure of
and
gases.
According to the Raoult's law,

where,
= partial pressure of gas
= total pressure of gas = 5.78 atm
= mole fraction of gas


and,


and,


Thus, the partial pressure of
and
gases are, 1.54, 1.03 and 3.20 atm respectively.
Answer:
False.
Explanation:
Technically it's false although many people think it is true. The property measured by temperature is Kinetic Energy. Temperature measures how fast particles are moving.
Answer:
7 to 4 (higher
)
5 to 3
3 to 2
4 to 2 (lower
)
Explanation:
We can use the Rydberg formula which relates the wavelength of the photon emissions to the principle quantum numbers involved in the transition:

with
final n, and
initial n
evaluating for each transition:
7 to 4 
5 to 3 
4 to 2 
3 to 2 
Note that the above formula is written for
, so lower
value obtained involves higher
.
So we should order from lower to higher 
7 to 4 (higher
)
5 to 3
3 to 2
4 to 2 (lower
)
Note: Take into account that longer wavelength involves lower energy (
).