Antacids

Introduction:
Antacids are a common medicine with a simple objective, which is to stabilize the PH of the gastric acids. To do this, it uses different bases that when reacting with the stomach acids, it neutralizes them for a given period of time (typically one hour). Some of the bases used are aluminum hydroxide, calcium carbonate, magnesium carbonate, magnesium hydroxide and sodium bicarbonate.

Uses:
To be able to digest food, one of the requirements for the stomach acids (gastric acids) is to have the ideal PH range between 1.5 and 3.5. This is necessary for the main digestive enzymes to work efficiently. The most common symptoms that antacids combat against are acid indigestion or heartburn. Acid indigestion is an illness in the stomach caused by two reasons; the first and most common one is by excess acid in the stomach that starts damaging the surrounding walls. The second reason is that the stomach walls lack protection, being damaged by the normal quantity of acid. Another symptom is heartburn. This problem is created when the stomach is full of food or gas, which makes the acids from the stomach go upward and out into the esophagus due to pressure; the esophagus is unprotected from any acid, which therefore gets burned. In both cases, antacids are used to regulate the gastric acid and increase its PH levels so that they stop burning and producing discomfort.

Reactions:
The gastric acids are mostly hydrochloric acid, therefore this reactions contain the coumpound bases and the hydrocloric acid. The reactions shows how the product of them are less acidic and the HCL is split to create other compounds.
 * Compound || Chemical Formula || Chemical Reaction ||
 * Aluminum hydroxide || Al(OH)3 || Al(OH)3(s) + 3 HCl(aq) -> AlCl3(aq) + 3 H2O(l) ||
 * Calcium carbonate || CaCO3 || CaCO3(s) + 2 HCl(aq) -> CaCl2(aq) + H2O(l) + CO2(g) ||
 * Magnesium carbonate || MgCO3 || MgCO3(s) + 2 HCl(aq) -> MgCl2(aq) + H2O(l) + CO2(g) ||
 * Magnesium hydroxide || Mg(OH)2 || Mg(OH)2(s) + 2 HCl(aq) -> MgCl2(aq) + 2 H2O(l) ||
 * Sodium bicarbonate || <span style="font-family: 'Times New Roman','serif'; font-size: 10pt; line-height: normal; margin: 0cm 0cm 0pt;">NaHCO3 || <span style="font-family: 'Times New Roman','serif'; font-size: 10pt; line-height: normal; margin: 0cm 0cm 0pt;">NaHCO3(aq) + HCl(aq) -> NaCl(aq) + H2O(l) + CO2(g) ||

Negative Effects:
Antacids also have negative effects on our body. This medicine relieves the symptoms of indigestion and heartburn, but only for a short period of time; after an hour, heartburn or indigestion rebound even worse than before, as the stomach tries to make up for the acid it lost. Secondly, antacids are advertised to be a good source of calcium; however, studies have shown that they actually block calcium absorption, as well as iron absorption. Thirdly, some antacids have large amounts of aluminum, an element which can block out mineral absorption, and in large quantities, cause harm to the nervous system. Lastly, the excessive use of antacids can cause vitamin and mineral deficiencies, as well as irreparable harm to your bones and organs.

Key terms:
Neutralization: The reaction between a base and an acid, which results in the formation of a salt and neutralized base. PH: A measure of the acidity or basicity

Sources:
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.2 Antacids (1h) B.2.1 State and explain how excess acidity in the stomach can be reduced by the use of different bases. Examples should include aluminium and magnesium compounds and sodium hydrogencarbonate. Students should be able to write balanced equations for neutralization reactions and know that antacids are often combined with alginates (which produce a neutralizing layer preventing acid in the stomach from rising into the esophagus and causing heartburn), and with anti-foaming agents (such as dimethicone).