The H+ concentration in the lake has increased as a result of the acid rain.
The original pH of the lake was 7, which mean the water is neutral, but due to the acid rain, it drops to 5. This means, that the water has become acidic and how have more hydrogen ion. The H+ concentration in the lake has 100 times compares with its original pH.
The oxidation state, sometimes referred to as oxidation number, describes the degree of oxidation of an atom in a chemical compound.
<u>Explanation:</u>
The oxidation number of an atom is the charge that atom would have if the compound was composed of ions. 1. The oxidation number of an atom is zero in a neutral substance that contains atoms of only one element. The oxidation number of simple ions is equal to the charge on the ion.
The oxidation number of a mono atomic ion equals the charge of the ion. The oxidation number of H is +1, but it is -1 in when combined with less electro negative elements. The oxidation number of O in compounds is usually -2, but it is -1 in peroxides. The oxidation number of a Group 1 element in a compound is +1.
<em>M CaCl₂: 40+(35,5×2) = 111 g/mol</em>
6,02·10²³ molecules ---------- 111g
X molecules --------------------- 75,9g
X = (75,9×<span>6,02·10²³)/111
X = <u>4,116</u></span><span><u>·10²³</u> molecules of CaCl</span>₂
:)