Chemical Reaction Unit Assessment

If Laila weighs the salt and vinegar solution and the pennies after the experiment, what do you think she will find?

• The solution will weigh more and the pennies will weigh less after the experiment.

• The solution will weigh less and the pennies will weigh more after the experiment.

• The solution will weigh the same and the pennies will weigh the same after the experiment.

• The solution will weigh the same and the pennies will weigh less after the experiment.

The graph shows how much the salt and vinegar solution weighed before the experiment. It also shows how much the pennies weighed before the experiment. Laila weighs the pennies after the experiment and finds that they weigh 8 grams. Draw on the bar graph to show how much the pennies weighed and how much the salt & vinegar solution weighed after the experiment.

Tags

CCSS.3.MD.B.4

Draw a model that represents what happens when vinegar and baking soda combine in an air-tight space. Include 4 steps in your model, draw things that are too small to see, and include labels.

Emi drops a cup of baking soda into a glass container that has vinegar at the bottom of it. Then, she quickly puts a balloon on top of the container. What do you predict will happen to the balloon?

• The balloon will get bigger because it will become filled with solid (baking soda) particles that are too small to be seen.

• The balloon will get bigger because it will become filled with liquid (vinegar) particles that are too small to be seen.

• The balloon will get bigger because it will become filled with gas particles that are too small to be seen.

• The balloon will stay the same because it will not become filled with anything.

Priya needs some baking soda to bake a cake. She has three white powders (salt, baking soda, and baking powder) in her kitchen, but they don’t have labels. She knows that baking soda will bubble and fizz if mixed with vinegar, but not with water. Baking powder will bubble and fizz if mixed with vinegar. It also bubbles when mixed with water. Salt does not bubble with vinegar or water. Priya conducts the following two experiments in her kitchen. If Priya only looks at the results of the Vinegar Experiment, what can she figure out?

• Either B or C is the baking soda. A must be the salt

• Either A or B is the baking soda. C must be the salt.

• Either A or C is the baking soda. B must be the salt.

• Priya can’t figure anything out if she only looks at the Vinegar Experiment.

Which of the three powders (Powder A, Powder B, or Powder C) do you think is the baking soda? Why do you think that? Support your answer with evidence from the experiments in complete sentences.

Dara learned something surprising at school. She likes drinking lemonade, orange juice, and tomato juice, and she learned that these are all acids. She wants to figure out which juice is the least acidic (a weak acid) and which is the most acidic (a strong acid). She knows that acids will react with baking soda, so she decides to use baking soda in her tests.

To figure out how strong of an acid each juice is, what should Dara do with the baking soda?

• Mix all of the juices together. Then, add some baking soda to the mix.

• Mix 10 milliliters of each juice with 1 gram of baking soda. Only mix one juice with baking soda at a time.

• Mix a few grams of baking soda with one juice first. Then, carefully mix in all of the other juices, too

• Mix 10 milliliters of two juices together at a time, but don’t add any baking soda.