<div>A group of students measured the pH of some substances they found in their homes. Their results are given in the following table:<table style=width:90%"><tr><td><b>Substance</b></td><td><b>pH</b></td><td><b>Substance</b></td><td><b>pH</b></td></tr><tr><td>Apples</td><td>3.0</td><td>Salt</td><td>7.0</td></tr><tr><td>Baking soda</td><td>8.5</td> <td>Sugar</td><td>7.0</td></tr><tr><td>Black coffee</td><td>5.0</td><td>Toothpaste</td><td>9.0</td></tr><tr><td>Household ammonia</td><td>12.0</td><td>Vinegar</td><td>3.0</td></tr><tr><td>Lemon juice</td><td>2.5</td> <td>Washing soda</td> <td>11.5</td></tr><tr><td>Milk</td> <td>6.5</td> </tr></table><b>(a)</b> What would the students have used to measure the pH ?<br><b>(b)</b> Which solution is the most acidic?<br><b>(c)</b> Which solution is the most alkaline?<br> <b>(d)</b> Which solutions are neutral?<br><b>(e)</b> Which solution can be used to treat wasp stings?<br><b>(f)</b> Which solution can be used to treat bee stings?</div>"