say for example, the color of our blood inside the body is blue, when you have a cut, th he blood color is red through oxygenation.
Answer is: the equilibrium concentrations fluorine anion are 0.004 M and lead cation are 0.002 M.<span>
Chemical reaction: PbF</span>₂(aq) → Pb²⁺(aq) + 2F⁻(aq).<span>
Ksp = 3,2·10</span>⁻⁸.
[Pb²⁺] = x.
[F⁻] = 2[Pb²⁺] = 2x<span>
Ksp = [Pb²</span>⁺] ·
[F⁻]².
Ksp = x · 4x².
3,2·10⁻⁸ = 4x³.
x = ∛3,2·10⁻⁸ ÷ 4.
x = [Pb²⁺] = 0,002M = 2·10⁻³ M.
[F⁻] = 2 · 0,002M = 0,004 M = 4·10⁻³ M.
Answer:
a solution color becoming less intense due to dilution- is not an evidence of a chemical reaction
bubbles (gas formation) - evidence of a chemical reaction
explosion or fire - evidence of a chemical reaction
changes in color- evidence of a chemical reaction
precipitation- evidence of a chemical reaction
changes in temperature - evidence of a chemical reaction
a solid liquifying - is not an evidence of a chemical reaction
solution colors mixing - is not an evidence of a chemical reaction
Explanation:
A chemical change is not easily reversible and yields new substances. It is often accompanied by a loss or gain of heat.
In the answer section, i have shown some evidences that lead us to conclude that a chemical reaction has taken place. The occurrence of a chemical change often goes with the formation of new substances as earlier stated and any of these signs may accompany the process.
For instance, when a metal is dropped in dilute acid solution, bubble of hydrogen gas indicates that a chemical reaction has taken place.
Zeff is the effective nuclear charge wherein, Z resembles the number of protons in the nucleus while S corresponds to the number of non-valence electrons.
Zeff = Z - S
Silicon has 14 protons; its electron configuration is [Ne] 3s2 3p2. Its
non-valence electrons is in the n = 1 and n =2 shells. There are 2
electrons in n = 1 and 8 in n = 2, so there are a total of 10
non-valence electron.
<span><span>Z<span>eff</span></span>= 14−10= 4</span>
So, the answer is 4.
