ΔHrxn = ΣδΗ(bond breaking) - ΣδΗ(bond making)
Bond enthalpies,
N ≡ N ⇒ 945 kJ mol⁻¹
N - Cl ⇒ 192 kJ mol⁻¹
Cl - Cl⇒ 242 kJ mol⁻¹
According to the balanced equation,
ΣδΗ(bond breaking) = N ≡ N x 1 + Cl - Cl x 3
= 945 + 3(242)
= 1671 kJ mol⁻¹
ΣδΗ(bond making) = N - Cl x 3 x 2
= 192 x 6
= 1152 kJ mol⁻¹
δHrxn = ΣδΗ(bond breaking) - ΣδΗ(bond making)
= 1671 kJ mol⁻¹ - 1152 kJ mol⁻¹
= 519 kJ mol⁻¹
Given the length of each side of a cube and its mass, the density can be obtained which can then help identify the type of material it's made of. This is because density is a unique and intrinsic property of materials. For this problem, the density is determined to be 10g/cm^3. Looking at a table of densities, the metal is most likely actinium, which has an exact density of 10 g/cm^3.
Answer:
b) 3.000 mol S
Explanation:
using Avogadro's constant
1 mol = 6.02 × 10^23 atoms
we need to find the number of moles for 1.806 × 10^24
x = 1.806 × 10^24
putting it together we now have:
1 mol = 6.02 × 10^23 atoms
x = 1.806 × 10^24
cross multiply
6.02 × 10^23 x = 1.806 × 10^24
divide both sides by 6.02 × 10^23
x = (1.806 × 10^24) ÷ (6.02 × 10^23) = 3 mol
The answer is b, because all of the other compounds are covelent
