Assignments III PreCalculus 12 26. The PH scale is used to measure the acidity or alkalinity of a solution. The pH of a solution is defined as pH = - log [H*], where [H*] is the hydrogen F1I Battery Acid ion concentration in moles per litre (mol/L). Increasing - Lemon Juice A neutral solution, such as pure water, has a pH of 7. Acidity -Vinegar Solutions with a pH of less than 7 are acidic and solutions with a pH of greater than 7 are basic or alkaline. The closer the pH is to 0, the more acidic the solution is. -Milk Neutral 7 (a) A common ingredient in cola drinks is phosphoric acid, the same ingredient CO found in many rust removers. -Baking Soda A cola drink has a pH of 2.5. Milk has a pH of 6.6. How many times as acidic 10 Milk of as milk is a cola drink? Increasing 11 Magnesia Alkalinity 12 - Ammonia 13 Lve 14 Cent Ans. (b) An apple is 5 times as acidic as a pear. If a pear has a pH of 3.8, then what is the pH of an apple? High school Ans. 27. If log 3 = P and log 5 = Q, write an algebraic expression in terms of P and Q for each of the following. (a) log 15 Ans. 25 ( b ) log , BEYOND THE LIMIT Ans. 11