Jhonna Fe M. Cipriano Zarah C. Abu III-Radon

QUESTIONS 1. What are the physical behaviour of acids and bases? 2. How do we differentiate an acid from a base? 3. How are the strengths of acids and bases identified? 4. How are bases and acids quantified? 5. What are pH indicators? 6. What are the common applications/uses of acids and bases?

Answer # 1.  Acids have a sour taste and release H- ions.  They are also soluble in water. They turn blue litmus paper into red and have pH values of  Most acid solutions are corrosive and react with reactive metals to form salt or hydrogen gas, metal carbonates to form salt, carbon dioxide and water and with bases or alkali to form salt and water neutralization. For bases Questions

 Bases taste bitter. A bitter taste is characteristic of all bases.  It is also slippery and turns a red litmus paper into blue.  Bases release hydroxide ions in water solutions.  Bases donate electrons for sharing with an electron-pair acceptor.  Bases raise its pH value when added to a solution. Questions

Answer # 2.  An acid is differentiated from a base using a litmus paper. When a litmus paper is sank in an acid solution, it changes the blue litmus paper into red but if a litmus paper is sank in a base solution, the color of the litmus paper will turn from red to blue.  pH levels are also used too. You can determine if a solution is a base when its pH level is 8-14 and if a solution is an acid when it's pH level is 0-6. Questions

Answer #3.  The strength of acids depend on the concentration of ionized Hydrogens.  For bases, this is determined by the completeness of the ionization into hydroxide and anions. Questions

Answer #4.  Acids and Bases are quantified by using the pH level scale.  Those pH levels from 0-6 are acids while those above 8 to 14 are bases.  7 in the scale is neutral. It is not an acid or a base. It is acidic if [H+] is greater than 1 x 10-7 M, basic if [H+] is less than1 x 10-7 M, and neutral if [H+] is equal to 1 x 10-7 M. Questions

Answer #5.  A pH indicator is a halochromic (a material which changes color when pH changes occur) chemical compound that is added in small amounts to a solution so that the pH (acidity or alkalinity) of the solution can be determined easily.  The indicator causes the colour of the solution to change depending on the pH. Questions

Answer # 6. Acids  Steel used in construction is acid treated before painting. Dilute sulfuric or hydrochloric acid will remove any surface rust which would otherwise spread under the painted surface. 'Rust remover' used to repair cars is dilute phosphoric acid - H 3 PO 4.  Baking powder contains tartaric acid. (used for cooking)  'Lime scale' removers contain dilute acids. Try using lemon juice or vinegar(weak acids). Lime scale is calcium carbonate.  A wasp sting is alkali. It may be neutralised with a weak acid (lemon juice or vinegar). QuestionsFor bases

Bases  Ammonium hydroxide, or ammonia water, is very irritating to the nose and the eyes. This substance, called a hydroxide, or a base, is often used in the home for cleaning because bases generally dissolve grease.  Milk of magnesia (magnesium hydroxide), which is used as an antacid, is a base; lye (sodium hydroxide), which is used in the manufacture of soap, is another familiar example of base. Questions