Liquids all around us have either acidic or basic ...



Liquids all around us have either acidic or basic (alkaline) properties. For example, acids taste sour; while, bases taste bitter and feel slippery. However, both strong acids and strong bases can be very dangerous and burn your skin, so it is important to be very careful when using such chemicals. In order to measure how acidic or basic a liquid is one must use the pH scale as illustrated below:

[pic]

Materials:

• Small cups

• Lemon Juice

• Sprite

• Vinegar

• Baking Soda solution

• Cleaner

• Sugar water

Procedure:

We will be testing for acids and bases by using an indicator. An indicator is a solution that changes color based on whether something is an acid or a base. We will be using red cabbage for this lab as our indicator. Red cabbage changes the following colors:

|pH |Color |

|2 |Red |

|4 |Purple |

|6 |Violet |

|8 |Blue |

|10 |Blue-green |

|12 |Greenish-yellow |

Therefore, if a solution is acidic, red cabbage will change it red. If it is basic, it will change a greenish-yellow color. For our experiment, we will be testing household items. You have in front of you containers of cabbage solution. Your job is to add the household items in front of you and record the color.

|Substance |Color |

|Sprite | |

|Baking soda solution | |

|Lemon juice | |

|Vinegar | |

|Cleaner solution | |

|Sugar water | |

Based on the colors you saw, which solutions do you think are acidic? Which ones are basic? Which ones are in the middle? Record your thoughts in the following table:

|Substance |Acid/Base/Neutral |

|Sprite | |

|Baking soda solution | |

|Lemon juice | |

|Vinegar | |

|Cleaner solution | |

|Sugar Water | |

Next:

Make a bar graph of the pH’s of these household items. Rank them from acids to bases. Place your bases on the right (greenish), your acids on the left (reds) and neutral pH’s (blues) in the middle.

| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |Procedure 2: Next we will be testing Diet Coke and Mentos and observing the reaction. To do this, you simply place a Mentos mint into a Diet Coke and observe what happens. Record your results by writing down what happens below:

Questions:

Why do you think the Diet Coke fizzes up when you drop a Mentos in it?

Lets see what Myth Busters has to say about it!

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download