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.
Answer:
NO.3) Mass of Al2O3 formed = 229.5g
D should be the correct answer :3
Answer:
6 Li(s) + N₂(g) → 2 Li₃N(s)
Explanation:
Solid lithium metal and diatomic nitrogen gas react spontaneously to form a solid product (lithium nitride). The chemical equation is:
Li(s) + N₂(g) → Li₃N(s)
Since the atomicities in the product are odd, the easiest way to balance the equation is by first multiplying it by 2.
Li(s) + N₂(g) → 2 Li₃N(s)
The final (balanced) equation is:
6 Li(s) + N₂(g) → 2 Li₃N(s)
Hey there!
The more energy a substance is, the more movement it has.
The energy of a substance determines its state of matter.
From least to most energy, it goes solid, liquid, gas.
So it needs to be going from a lower energy state to a higher energy state.
The only one that goes from a lower energy state to a higher energy state is C. H2O (l) --> H2O (g).
Hope this helps!
