LeChatelier's Principle
Ben, Iain, Cara, Cheryl
Solubility of Carbon Dioxide
The decrease in pressure caused a shift towards the reactants and the solution became less acidic. LeChatelier's principle states that when the pressure is decreased the equilibrium shits towards the side that reduces moles of gas. The color of the original was light green, while the one with less pressure is blue. Blue is less acidic on the pH indicator scale.
Solubility of Magnesium Hydroxide
The equilibrium shifted towards the products because HCl reacted with the OH ions produced.
Mg(OH)2 --> Mg + 2OH
OH + H --> H2O
10 pH
The indicator was purple because of the presence of OH
7-8 pH
The indicator changed from blue to green from the presence of H being added through the HCl. The H from HCl is reacting with the OH to make H2O. This caused the pH to raise since H2O is more acidic than OH.
4 pH
The indicator stayed at pink because all of the OH was used up, and there was an excess of HCl left in the solution. Pink is the most acidic on the pH list.