DeltaH formation = deltaH of broken bonds - deltaH of formed bonds
Broken bonds: tiple bond N-N and H-H bond
Formed bonds: N-H and N-N bonds
You also have to take note of the molar coefficients
deltaH formation = <span> [(N≡N) + 2 * (H-H)] - [4 * (N-H) + (N-N)]
= (945 + 2*436) - (4*390 + 240)
= 17 kJ/mol
The answer is 17 kJ/mol.</span>
Isotope atoms mean, atoms with the same number of protons but different number of neutrons in their nuclei . The given oxygen atoms are isotopes meaning they have different number of neutrons in their nuclei . Oxygen 16 have 8 protons and 8 neutrons in its nucleus but Oxygen has 8 protons and 10 neutrons. That's what make them different.
Lets name the unknown metal as M. Cation would be M³⁺.
the molecular formula of the compound is M₂(SO₄)₃
the mass of one mole - (molar mass of M x2 + 3 x molar mass of SO₄²⁻)
= 2M + 96 x 3
= 2M + 288
In 1 mol if there's 72.07% of sulphate ,
then 72.07 % corresponds to 288 g
1 % is then - 288/72.07
100 % of the compound - 288/72.07 x 100
molar mass of the compound - 399.6 g/mol
mass of 2M - 399.6 - 288 = 111.6 g
molar mass of M - 111.6 /2 = 55.8 g/mol
the element with molar mass of 55.8 is Fe.
Unknown metal is iron(III) , Fe³⁺
Answer:

Explanation:
Let's rewrite the given word equation in its chemical balanced equation representation:
1. Lead(II) nitride is represented by lead, Pb, in an oxidation state of 2+, while nitride is a typical nitrogen anion with a state 3-. As a result, the lowest common multiple between 2 and 3 is 6, meaning 2 lead cations are needed to balance 3 nitrogen anions:
.
2. Ammonium sulfate consists of an ammonium cation with a 1+ charge and sulfate anion with a 2- charge, two ammonium cations needed:
.
3. Lead(II) sulfate would have one lead cation and one sulfate anion, as they have the same magnitude of charges with opposite signs:
.
4. Ammonium nitride would require three amonium cations to balance the nitride anion:
.
Let's write the balanced equation:

Neutralization reaction??