Lead is often used to block out radiation
Answer:
C) MnO₂
Explanation:
If we write the semi equations (this is, for reduction and oxidation) we will have:
Oxidation: 2MnO₂ → MnO₄⁻ + Mn⁺²
Reduction: 2H₂O → H₂ + 2OH⁻
Then the final global reaction (just adding the two above hemi chemical reactions):
2MnO₂ + 2H₂O → MnO⁻₄ + Mn⁺² + H₂ + 2OH⁻ (in acidic media)
So, we have Mn⁺⁴ (from MnO₂) goes to Mn⁺⁷ and Mn⁺² (this is, Mn is oxidated) and H⁺ (from acidic media or H₂O) goes to H₂ (this is, it is reduced). So the reducing agent would be MnO₂
Answer:
SO42 - Trigonal planar ion
Explanation:
The SO4^2- ion is tetrahedral and not trigonal planar because the sulphur atom has four regions of electron density which includes the lone pair of electrons on sulphur atom.
This accounts for the observed tetrahedral arrangement of electron pairs around the central sulphur atom in SO4^2- ion, hence the answer.
Answer: 19kpa
Explanation:
The total pressure of a mixture of gases is the sum of the partial pressure exacted by the individual gases.
P total = P X + P Y
From the question above:
P total = P .nitrogen + P. oxygen
123.5kpa = 104.5kpa + P. Oxygen
P. Oxygen = 123.5kpa - 104.5kpa
= 19kpa
