Magnesium

The reaction between magnesium hydroxide (Mg(OH)₂) and hydrofluoric acid (HF) can be represented by the following equation:

[ \text{Mg(OH)}_2 + 2\text{HF} \rightarrow \text{MgF}_2 + 2\text{H}_2\text{O} ]

In this reaction, magnesium hydroxide reacts with hydrofluoric acid to produce magnesium fluoride (MgF₂) and water (H₂O).

Magnesium itself is a metal and does not classify as an acid or alkali. However, when it reacts with acids, it can produce hydrogen gas and magnesium salts, indicating its reactivity with acidic substances. In the presence of water, magnesium oxide can form magnesium hydroxide, which is a weak alkaline solution. Thus, magnesium's behavior in chemical reactions determines its classification in relation to acids and alkalis, but it is not inherently one or the other.

Ionic bonding between magnesium and chlorine occurs when magnesium, a metal, loses two electrons to achieve a stable electron configuration, becoming a positively charged ion (Mg²⁺). Chlorine, a non-metal, gains these two electrons to form two negatively charged chloride ions (Cl⁻). The electrostatic attraction between the positively charged magnesium ions and the negatively charged chloride ions results in the formation of magnesium chloride (MgCl₂), a stable ionic compound. This transfer of electrons and subsequent attraction is the essence of the ionic bonding process.

When magnesium combines with sulfur to form magnesium sulfide (MgS), magnesium is oxidized, meaning it loses electrons. In this reaction, magnesium (Mg) has an oxidation state of 0 in its elemental form and is oxidized to Mg²⁺, while sulfur (S) is reduced from an oxidation state of 0 to S²⁻. The overall process involves the transfer of electrons from magnesium to sulfur, resulting in the formation of the ionic compound MgS.

To calculate the number of magnesium (Mg) atoms in 2 grams of chlorophyll, we first need to determine the molar mass of chlorophyll, which is approximately 893.49 g/mol. Since chlorophyll contains 2.68% magnesium, the mass of magnesium in 2 grams of chlorophyll is 0.0536 grams. The number of moles of magnesium is calculated by dividing the mass by its atomic mass (24.31 g/mol), resulting in approximately 0.0022 moles. Finally, multiplying by Avogadro's number (6.022 x 10²³) gives about 1.32 x 10²¹ atoms of magnesium in 2 grams of chlorophyll.

To determine the mass of hydrogen produced, we first need to identify the balanced chemical reaction between magnesium and water:

[ \text{Mg} + 2\text{H}_2\text{O} \rightarrow \text{Mg(OH)}_2 + \text{H}_2 ]

Next, we calculate the moles of magnesium (4.73 g / 24.31 g/mol = 0.194 moles) and water (1.83 g / 18.02 g/mol = 0.101 moles). Since magnesium reacts with water in a 1:2 ratio, magnesium is the limiting reactant. Therefore, 0.194 moles of magnesium will produce 0.194 moles of hydrogen gas, which corresponds to about 0.194 moles × 2 g/mol = 0.388 g of hydrogen.

Acid + a Metal = a salt + hydrogen Mg + H2SO4-----> MgSO4 + H2