I believe the answer is D. An ion always has a positive or a negative charge. An Ion is an atom with net electric charge due to the loss or gain of one or more electrons. An isotope is each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their neutron, thus they differ in relative atomic mass but not in chemical properties.
Make note of it and learn from her mistakes :)
Phosphoric acid has 3 pKa values (pKa1=2.1, pKa2=6.9, pKa3= 12.4) and after 3 ionization it gives 3 types of ions at different pKa values:
H₃PO₄(aq) + H₂O(l) ⇌ H₃O⁺(aq) + H₂PO₄⁻ (aq) pKₐ₁
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</span>H₂PO₄⁻(aq) + H₂O(l) ⇌ H₃O⁺(aq) + HPO₄²⁻ (aq) pKₐ₂
HPO₄²⁻(aq) + H₂O(l) ⇌ H₃O⁺(aq) + PO₄³⁻ (aq) pKₐ₃
The last equilibrium is associated with the highest pKa value (12.4) of phosphoric acid. There the last OH group will lose its hydrogen and hydrogen phosphate ion (HPO₄²⁻) turns into phosphate ion (PO₄³⁻).
Answer :
Formal charge on C: (-1)
Formal charge on N: (0)
Net charge: (-1)
Explanation :
First we have to determine the Lewis-dot structure of 
.
Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.
In the Lewis-dot structure the valance electrons are shown by 'dot'.
The given molecule is,
As we know that carbon has '4' valence electrons and nitrogen has '5' valence electrons.
Therefore, the total number of valence electrons in = 4 + 5 + 1= 10
According to Lewis-dot structure, there are 6 number of bonding electrons and 4 number of non-bonding electrons.
Now we have to determine the formal charge for each atom.
Formula for formal charge :
Net charge = -1 + 0 = -1
Answer:
molar mass M(s) = 65.326 g/mol
Explanation:
- M(s) + H2SO4(aq) → MSO4(aq) + H2(g)
∴ VH2(g) = 231 mL = 0.231 L
∴ P atm = 1.0079 bar
∴ PvH2O(25°C) = 0.03167 bar
Graham´s law:
⇒ PH2(g) = P atm - PvH2O(25°C)
⇒ PH2(g) = 1.0079 bar - 0.03167 bar = 0.97623 bar = 0.9635 atm
∴ nH2(g) = PV/RT
⇒ nH2(g) = ((0.9635 atm)(0.231 L))/((0.082 atmL/Kmol)(298 K))
⇒ nH2(g) = 9.1082 E-3 mol
⇒ n M(s) = ( 9.1082 E-3 mol H2(g) )(mol M(s)/mol H2(g))
⇒ n M(s) = 9.1082 E-3 mol
∴ molar mass M(s) [=] g/mol
⇒ molar mass M(s) = (0.595 g) / (9.1082 E-3 mol)
⇒ molar mass M(s) = 65.326 g/mol
