Answer : The pressure in the flask after reaction complete is, 2.4 atm
Explanation :
To calculate the pressure in the flask after reaction is complete we are using ideal gas equation.

where,
P = final pressure in the flask = ?
R = gas constant = 0.0821 L.atm/mol.K
T = temperature = 
V = volume = 4.0 L
= moles of
= 0.20 mol
= moles of
= 0.20 mol
Now put all the given values in the above expression, we get:


Thus, the pressure in the flask after reaction complete is, 2.4 atm
Answer:
How can you distinguish a physical change from a chemical change?
Explanation:
Answer:
evaporated
Explanation:
Once the solution is evaporated there will only be salt left, since the only other thing in the soulution is water.
Explanation:
The given data is as follows.
= 253.4 nm =
(as 1 nm =
)
= 5,
= ?
Relation between energy and wavelength is as follows.
E = 
= 
=
J
= 
Hence, energy released is
.
Also, we known that change in energy will be as follows.

where, Z = atomic number of the given element


0.02 + 0.04 = 
= 
= 4
Thus, we can conclude that the principal quantum number of the lower-energy state corresponding to this emission is n = 4.