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:
Explanation:
The<em> energy of a photon</em>, E, can be calculated with the Planck-Einstein equation:
Where:
- h is Planck's constant 6.626×10⁻³⁴ J.s, and
- f is the frequency of the photon or electromagnetic radiation.
Substituting with your data:
Now multiply by Avogadro's number to obtain the energy of one mole of photons:
There is this thing called isotopes
it means that atoms of the same element can have a different number of neutrons.
if there is a change in the no. of neutrons, there will definitely be a change in the mass number.
so the answer is A) mass number
Answer:
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- <u>There are 0.041 g of NH₃ in the same number of molecules as in 0.35 g of SF₆.</u>
<u />
Explanation:
Using the molar mass of the chemical formula SF₆ you can find the number of moles of molecules in 0.35 g of such substance. Then, using the molar mass of NH₃, you can find mass in grams corresponding to the same number of molecules.
<u>1. Find the molar mass of SF₆:</u>
Atom atomic mass number of atoms total mass in 1 mole
S 32.065 g/mol 1 32.065 g
F 18.998 g/mol 6 6 × 18.998 = 113.988 g
=====================
molar mass of SF₆ = 146.053 g/mol
<u>2. Find the number of moles in 0.35 g of SF₆:</u>
- number of moles = mass in grams / molar mass
- number of moles = 0.35 g / 146.053 g / mol = 0.0024 mol
<u>3. Find the molar mass of NH₃:</u>
Atom atomic mass number of atoms total mass 1 mole
N 14.007 g/mol 1 14.007 g
H 1.008 g/mol 3 3 × 1.008 g = 113.988 g
=====================
molar mass of NH₃ = 17.031 g/mol
<u />
<u>4. Find the mass in 0.0024 mol of NH₃:</u>
- mass in grams = number of moles × molar mass
- mass = 0.0024 mol × 17.031 g/mol ≈ 0.041 grams
<u>5. Conclusion: </u>
There are 0.041 g of NH₃ in the same number of molecules as in 0.35 g of SF₆.
The Lewis structure of PF3 shows that the central phosphorus atom has one non bonding and three bonding electron pairs. In this compound each Phosphorus atom contributes 5 valence electrons while each fluoride contributes 7 valence electrons making a total of 26 valence electrons. The central Phosphorus atom forms single bonds with each of the fluoride atoms. Phosphorus, therefore ends up with a non-bonding pair since the fluoride atoms already have 8 electrons around them. <span />
