Answer:
Overall, ethanol is considered to be better for the environment than petrol. Ethanol-fuelled vehicles produce lower carbon dioxide emissions, and the same or lower levels of hydrocarbon and oxides of nitrogen emissions.
Explanation:
Answer:

Explanation:
Double Bond => An Alkene molecule
So, the suffix will be "-ene"
7 Carbons => So, we'll use the prefix "Hept-"
Combining the suffix and prefix, we get:
=> Heptene
Hg + O2 --> HgO + O
Note that Mercury has a variable valency.
Answer: The precipitate formed is 
Explanation:
A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid or precipitated form are represented by (s) after their chemical formulas.
A double displacement reaction in which one of the product is formed as a solid is called as precipitation reaction.
The balanced chemical equation is:

Answer:
c) (12×0.9889) + (13×0.01108)
Explanation:
Given data:
Percentage of C-12 = 98.89%
Percentage of C-13 = 1.108%
Atomic mass = ?
Solution:
98.89/100 = 0.9889
1.108/ 100 = 0.01108
Atomic mass = (12×0.9889) + (13×0.01108)
Atomic mass = (11.8668 + 0.144034)
Atomic mass = 12.01084