<span>When two or more substances are mixed together but not chemically joined they are called as mixtures. Therefore, it is only a physical change taking place.
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Answer:
Silver tarnishes and becomes black when exposed to oxygen:
Diesel fuel burns when it is heated:
Explanation:
Chemical Changes are those changes in which the chemistry at molecular level is changed as the starting material is converted in to a new and different final material. This change takes place with the breaking of old bonds and forming of new bonds respectively.
Silver tarnishes and becomes black when exposed to oxygen:
This is a chemical change as Silver a white and lustrous starting material is being converted into a tarnish black final material. However, Silver doesn't readily react with oxygen at normal conditions. It readily react with Sulfur containing compounds in air and produces black compound as Ag₂S.
Diesel fuel burns when it is heated:
Diesel is a mixture of hydrocarbons ranging approximately from C₁₀H₂₀ to C₁₅H₂₈. When these hydrocarbons are burnt they produces a new materials i.e. CO₂ and H₂O.
C₁₀H₂₀ + 15 O₂ → 10 CO₂ + 10 H₂O
Hence, it is also a chemical reaction.
Answer:
H₂SO₄ (aq) + H₂O (l) → HSO₄⁻ (aq) + H₃O⁺ (aq)
HSO₄⁻ (aq) + H₂O (l) ⇄ SO₄⁻²(aq) + H₃O⁺ (aq) Ka
Explanation:
The sulfuric acid is a dyprotic acid.
It is a considered a strong acid but only the first deprotonation is strong.
Second deprotonation is totally weak
That's why we have equilibrium when it release the second proton.
Since a deprotonation is treated for a weak acid, the acid is considered not to completely dissociate, that's why the equilibrium
Answer:
it's A but I don't know the other one
