You know what I love? A fun and easy kids' activity that uses up things you have around the house. You know what I also love? Recipes that don't involve measuring anything! Welcome to baking soda and vinegar fizzy painting, which combines the best of both worlds. To sum up this DIY project in two words, I'll quote my two-year-old: "Oh, wow!"
A glass baking dish (or pan with raised sides)
Small bowls for your vinegar "paint"
A medicine dropper and/or spoons
Pour a nice, snowy layer of baking soda into your baking dish—or really, any container with sides (you don't want your fizzy painting to overflow). You'll probably want to do this activity far away from a carpeted surface. It's not like you're going to end up with a grade school science-fair volcano eruption, but both my toddler and I ended up dripping food coloring everywhere. So choose an easily-wiped-down surface to play on. We got down (and mildly, colorfully dirty) on the floor.
Mix vinegar with your choice of food coloring to make your fizzy "paint." I used quite a few drops of dye to make a rosy red and bold blue, as the color will fade a bit once it mixes with the baking soda. After you've stirred your colors (and removed any all-white clothing your toddler is wearing), you're ready to "paint." Dip your medicine dropper into the vinegar dye, then dribble, drip, and drop the colors all over your baking-soda landscape. As soon as the vinegar dye hits your good ol' NaHCO3, it will bubble up and make an awesome fizzing sound. Again, to quote my toddler, "Oh, wow!"
My little guy was totally entranced with the fizzing component of this activity. He had a little trouble getting the medicine dropper completely full on his own, so we switched over to spoons and even a used plastic coffee-creamer container. You could really use any kitchen item you like—measuring cups, spoons, or straws. Whatever gets a goodly amount of vinegar dye onto the baking soda will work; just remember—the more vinegar you pour at one time, the more exciting bubbling will occur. After the chemical reaction subsides, the color fades and you're left with a cool pastel, volcanic-rock design.
This DIY project was fun, easy to set up, and easy to clean. I have to say, as I was not a stickler about keeping my kiddo's hands and fingers out of the dye, he did have purple fingers for the rest of the day. But hey, that's a small price to pay for some good play!