95: Antacids are often used to relieve pain and promote healing in the treatment of mild ulcers. Write balanced net ionic equations for the reactions between the aqueous HCI in the stomach and each of the following substances used in various antacids: (a) AI(OH)3(s), (b) Mg(OH)2(s), (c) MgCO3(s), (d) NaAI(CO3)(OH)2(s), (e) CaCO3(s).
Solution: Here, we are going to write the net ionic equations for the reaction between HCl and the given substances used in various antacids. Step1: Antacids are the substances which neutralizes the effect of an acid in our body. They are composed of bases which undergoes neutralization reactions with acid to produce neutral solution of water and salt. Net ionic equation shows only those chemical species which are taking part in a chemical reaction. while writing the ionic equation, we write out all the soluble compounds as ions and eliminate ions common to both the reactants and products. This will give us the net ionic equation. Step2: Let us write the balanced molecular and net ionic equations for the reaction between HCl and the bases present in the antacids: a) HCl reacts with Al(OH) to produce aluminium chloride and water. The balanced 3 molecular equation for the above reaction is: 3HCl(aq) + Al(OH) (s) ----3-> AlCl (aq) + 3H O 3 2 Using the guidelines of solubility, we can say that Al(OH) is insoluble in water3nd hence will not be dissociated into ions. So, the balanced ionic equation for the above reaction is: + - 3+ - 3H + 3Cl + Al(OH) ---------3-> 3H O + Al + 3Cl2Al(OH) being 3 insoluble cannot be converted into ions] Eliminating common ions on both sides of the equation, we get the net ionic equation as follows: + 3+ 3H + Al(OH) (s) --3--------> 3H O + Al 2 Step3: b) HCl reacts with Mg(OH) to produce magn2ium chloride and water. The balanced molecular equation for the above reaction is: 2HCl(aq) + Mg(OH) (s) -------> MgCl (aq) + 2H O 2 2 2 Using the guidelines of solubility, we can say that Mg(OH) is insoluble in water a2 hence will not be dissociated into ions. So, the balanced ionic equation for the above reaction is: 2H + 2Cl + Mg(OH) ------------> 2H O + Mg + 2Cl [Mg(OH) being+ - 2 2 2 insoluble cannot be converted into ions] Eliminating common ions on both sides of the equation, we get the net ionic equation as follows: + 2+ 2H + Mg(OH) (s) ------2----> 2H O + Mg 2 Step4: c) HCl reacts with MgCO...
