1. The test tube that contained the calcium metal was

1. The test tube that contained the calcium metal was probably the most difficult of the test tubes to clean. Why was aqueous HCl used to clean the test tube? Write the balanced chemical equation fo the reaction that took place in this test tube as part of your answer. (little if any unreacted Ca metal was left in that tube-what chemical was produced in this reaction?)

2. (Reactivity of metals) It took many of the metals several minutes to begin to react. Once the reaction was initiated, several of these metals continued to react quite vigorously. What was the most probable cause fo this delayed reaction? (The metal getting hot isn’t the only reason.)