Answer:
Fossil fuels contribute to greenhouse gases, which is one of their major disadvantages. The most harmful for the environment is coal because it has many more harmful combustion products than other fossil fuels.
Answer:
6.54% is the required concentration of lithium in an alloy (Al–Li).
Explanation:
Suppose 100 grams of an alloy of aluminium and lithium.
Density of an alloy = d 
Volume of an alloy = V
Volume of aluminum = 
Mass of aluminum = x
Density of aluminum = 
Volume of lithium = 
Mass of lithium = y
Density of lithium= 
..[1]
..[2]
Solving [1] and [2] :
we get :
x = 93.46 g
y = 6.54 g
Concentration of Li (in wt%) that is required:
Answer:
Reduction
Explanation:
Reduction:
Reduction involve the gain of electron and oxidation number is decreased.
Mn⁺⁷ +3e⁻ → Mn⁴⁺
Mn gets three electrons , its oxidation state reduced from +7 to +4 so Mn gets reduced.
Examples:
Consider the following reactions.
4KI + 2CuCl₂ → 2CuI + I₂ + 4KCl
the oxidation state of copper is changed from +2 to +1 so copper get reduced.
CO + H₂O → CO₂ + H₂
the oxidation state of carbon is +2 on reactant side and on product side it becomes +4 so carbon get oxidized.
H₂S + 2NaOH → Na₂S + 2H₂O
The oxidation sate of sulfur is -2 on reactant side and in product side it is also -2 so it neither oxidized nor reduced.
Ionic bonds involve a cation and an anion. The bond is formed when an atom, typically a metal, loses an electron or electrons, and becomes a positive ion, or cation. Another atom, typically a non-metal, is able to acquire the electron(s) to become a negative ion, or anion.
One example of an ionic bond is the formation of sodium fluoride, NaF, from a sodium atom and a fluorine atom. In this reaction, the sodium atom loses its single valence electron to the fluorine atom, which has just enough space to accept it. The ions produced are oppositely charged and are attracted to one another due to electrostatic forces.
is aluminium oxide (also called aloxide, aloxite and alundum). It is neither acid nor base. It has amphoteric nature meaning it can act as an acid with bases and as a base with acids. It neutralises them to salts.
