Answer:
16.8128 grams of sodium azide is needed
Explanation:
2NaN3 = 2Na + 3N2
molar mass of NaN3 =
molar mass of N2
moles of N2 =
moles=mass/R.F.M
16.55÷42 = 0.3940
mole ratio=
2NaN3 : 3N2
3 = 0.3940
2=?
Mass of sodium azide =64×0.2627
=16.8126
Answer:
450.0 L.
Explanation:
- We can use the general law of ideal gas: <em>PV = nRT.</em>
where, P is the pressure of the gas in atm.
V is the volume of the gas in L.
n is the no. of moles of the gas in mol.
R is the general gas constant,
T is the temperature of the gas in K.
- If n and T are constant, and have different values of P and V:
<em>(P₁V₁) = (P₂V₂).</em>
<em></em>
V₁ = 760.0 L, P₁ = 450.0 mm Hg,
V₂ = ??? L, P₂ = 760.0 mm Hg (standard pressure = 1.0 atm = 760 mm Hg).
∴ V₂ = (P₁V₁)/(P₂) = (760.0 L)(450.0 mm Hg)/(760.0 mm Hg) = 450.0 L.
3. Atoms change into other atoms in chemical reactions.
The idea that you can transform one element into another was called alchemy, and was proven untrue a long time ago.
Answer:
Explanation:
the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.
the total number of protons and neutrons in a nucleus.
to write the symbol for an isotope, place the atomic number as a subscript and the mass number (protons plus neutrons) as a superscript to the left of the atomic symbol
Answer:
a) +640 kJ/mol or +1.06x10⁻¹⁸ J
b) +276 kJ/mol
Explanation:
To dissociate the molecule, the bond must be broken, thus, it's necessary energy equal to the energy of the bond, which can be calculated by:
E = (Q1*Q2)/(4*π*ε*r)
Where Q is the charge of the ions, ε is a constant (8.854x10⁻¹²C²J ⁻¹ m⁻¹), and r is the bond length. Each one of the ions has a charge equal to 1. The elementary charge is 1.602x10⁻¹⁹C, which will be the charge of them.
1 mol has 6.022x10²³ molecules (Avogadros' number), so the energy of 1 mol is the energy of 1 molecule multiplied by it:
E = 6.022x10²³ *(1.602x10⁻¹⁹)²/(4π*8.854x10⁻¹²*2.17x10⁻¹⁰)
E = +640113 J/mol
E = +640 kJ/mol
Or at 1 molecule: E =640/6.022x10²³ = +1.06x10⁻²¹ kJ = +1.06x10⁻¹⁸ J
b) The energy variation to dissociate the molecule at its neutral atoms is the energy of dissociation less the difference of the ionization energy of K and the electron affinity of F (EA):
498 = 640 - (418 - EA)
640 -418 + EA = 498
222 + EA = 498
EA = +276 kJ/mol
