Answer:
Pure water is a non conductor of electricity and dilute acids in their aqueous solutions form free ions, which conducts electricity. Thus when we need to electrolyse water, a dilute acid is added to increase its conductivity.
To know the answer, compare the oxidation number of the element in the reactant and the product side. The oxidation number of Al was originally +3, then became 0 after the reaction. On the other hand, Fe was originally 0, then became +2 after the reaction. When the element is oxidized, it oxidation number increases. <em>Thus, the element oxidized is Fe.</em>
Answer:
2.4
⋅
10
24
Explanation:
All that you need to know here is that in order for a given sample of water to contain exactly 1 mole of water, it must contain 6.022
⋅
10
23 molecules of water.
This is known as Avogadro's constant and essentially acts as the definition of a mole. If you have 6.022
⋅
10
23 molecules of water, then you can say for a fact that you have 1 mole of water.
