The correct answers are options C, that is, silver tarnishes and becomes black when exposed to oxygen, and option E, that is, diesel fuel burns when it is heated.
Chemical changes refer to the modifications in which the chemistry at molecular level is modified as the initial substance gets transformed into a new and different final substance. This change occurs with the dissociation of old bond and production of new bonds respectively.
Silver gets tarnished and becomes black when exposed to oxygen. This refers to a chemical change as silver a white and lustrous substance gets transformed into a tarnish black final substance. However, silver does not easily react with oxygen at usual circumstances. It easily reacts with sulfur comprising components in the air and generates black compound as Ag₂S.
Burning of diesel fuel when it is heated. Diesel refers to a mixture of hydrocarbons varying approximately from C₁₀H₂₀ to C₁₅H₂₈. When these hydrocarbons get burnt they generate novel substances, that is, carbon dioxide and water. Hence, it is also a chemical reaction.
According to google, one gallon equals 8.36 pounds. I took 8.36and divided by 0.00590 and got 1416.94915254 So if rounded to the nearest hundreth, 1416.95. I have no idea if I'm right. Sorry I couldn't do more!
Some parts of a plant can be white because they do not contain chlorophyll.
Chlorophyll is a term to refer to a characteristic compound of most plants that has the function of:
- Bring the green color to vegetables
- Take charge of the photosynthesis process.
Some plants do not have as much chlorophyll in their systems. However, this does not affect their reproduction and growth because they have developed other feeding methods through their roots.
These plants that contain low amounts of chlorophyll have pale and white colorations because chlorophyll is what gives the plants their intense green color.
Note: This question is incomplete because options are missing. Nevertheless, I can answer it based on my prior knowledge.
Learn more in: brainly.com/question/14884020
We are given the base dissociation constant, Kb, for Pyridine (C5H5N) which is 1.4x10^-9. The acid dissociation constant, Ka for the Pyridium ion or the conjugate acid of Pyridine is to be determined. We know from our chemistry classes that:
Kw = Kb * Ka
where Kw is always equal to 1x10^-14
so, to solve for Ka of Pyridium ion, substitute Kb to the equation together with Kw and solve for Ka:
1x10^-14 = 1.4x10^-9 * Ka
solve for Ka
Ka = 7.14x10^-6
Therefore, the acid dissociation constant of Pyridinium ion is 7.14x10^-6.
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