The substance which has definite composition with definite physical and chemical properties is said to be pure substance. These substances are not separated by the different physical techniques such as filtration, distillation, evaporation etc.
The clear water pumped from a deep aquifer is a pure substance because water is a pure compound which consist of constant single type of atoms or group of atoms and water has specific value of boiling and melting point. Water is also not separated into units or constituents by physical technique.
Hence, clear water pumped from a deep aquifer is a pure substance.
Answer:
5 moles of Fe
Explanation:
The equation of the reaction is;
2 Al(s) + Fe 2O 3(s) --> 2Fe (s) + Al 2O 3 (s)
Now;
1 mole of Fe2O3 require 2 moles of Al
3 moles of Fe2O3 requires 3 × 2/1 = 6 moles of Al
Hence Al is the limiting reactant.
If 2 moles of Al yields 2 moles of Fe
5 moles of Al yields 5 × 2/2 = 5 moles of Fe
Noice but I don’t get why was this necessary
Neutralization reaction takes place between an acid and a base to form salt and water.
In the given reaction the acid is hydrochloric acid HCl and the base is aluminum hydroxide (Al(OH)
).
The correct balanced equation for the neutralization reaction that occurs between aluminum hydroxide and hydrochloric acid can be represented as:
Al(OH)can give 3 hydroxide, 
ions which can neutralize the 3 
ion produced by 3 HCl molecules giving 3 mole of water and the salt aluminum chloride, AlCl.
Therefore the correct option will be.
D. Al(OH)3 + 3 HCl (aq) --> AlCl3(aq) + 3 H2O(l)
