You don't need a fancy chemistry set with lots of different chemical and tools to conduct science experiments. Several fun and interesting projects require only vinegar and water in addition to a few ingredients found in most home kitchens. To make a project into a scientific experiment, guess or hypothesize what your results will show, record the steps you take and the ultimate conclusion. Finally describe what you learned from the experiment, and whether your hypothesis was proven correct or incorrect.
For this experiment you need water, vinegar, 2 tablespoons baking soda, a zipper-locking style plastic bag that does not have any holes and seals tightly, a paper towel and a measuring cup. Cut the paper towel into a 6-inch by 6-inch square and put the baking soda in the center. Fold the paper towel around the baking soda so the baking soda won't leak out. Pour 1/2 cup vinegar and 1/4 cup warm water into the baggie. Zip the bag part-way closed, drop in the paper towel packet of baking soda and quickly seal the baggie. Carbon dioxide created when the baking soda and vinegar mix will cause the bag to expand and pop.
Soft Shell Egg
For this experiment you need a raw egg, 1 cup vinegar, two clear jars and water. Pour the vinegar into one jar. Carefully place the raw egg into it. Let the egg sit in the vinegar for 24 hours. When you remove it, notice how the egg shell has changed. Place the egg in a jar full of warm water and watch what happens. The vinegar draws calcium out of the shell, making it soft. When you place the egg in water, the water moves into the egg shell through osmosis until it breaks the shell. Osmosis happens when a liquid moves through a membrane because the pressure is lower on the other side.
For this experiment you need long, thin chicken bones and vinegar. Place the bones in vinegar and let them soak for 24 hours. When you take the bones out of the vinegar, they will feel flexible. Tie the bones in a knot, and let them sit out for 24 hours. The bones will get hard and inflexible again. Vinegar pulls calcium carbonate from the bones which makes them soft. During the time they sit out, the calcium left in the bones pulls carbon back in, making them hard.
Freezing Speed of Vinegar and Water
For this experiment you need one jar filled with half vinegar and half water, and another filled with only water. Place both jars in the freezer and watch to see which liquid freezes first. You should see that the vinegar mixture freezes before the pure water. This happens because vinegar consists of water and acetic acid. The acetic acid forms strong bonds with water molecules. These bonds slow the movement of the molecules in the solution faster than molecules in pure water, causing the solution to freeze more quickly.