Ammonia isn't an element, it's a compound made by mixing the elements Nitrogen and Hydrogen in the Haber process. Therefore, it isn't on the periodic table
Answer:
Explanation:
Its chemical formula is Fe2(SO4)3
mol CaCl₂ = 1.2 x 10²⁴ : 6.02 x 10²³ = 1.993
mass = 1.993 x 111 g/mol = 221.223 g
Answer:
Volume of acid in the solution, 53.87 mL
Explanation:
This can be solved with a simple formula
(Volume of solution which is acid / Total volume) . 100 = % acid
(Volume of solution which is acid / 341 mL) . 100 = 15.8
Volume of solution which is acid / 341 mL = 0.158
Volume of solution which is acid = 0.158 . 341 mL
Volume of solution which is acid = 53.87 mL
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
