Question

Obtain small pieces of zinc (zn), copper (cu), and magnesium (mg). Observe and record the appearance of each. Place 3 ml of 1 M HCl(aq) in each of three test tubes. Carefully add a different metal to each of the HCl test tubes. Observe and record any sign of a reaction for each metal. Remember to carefully feel the temperature of each test tube. What is the result of adding zinc (Zn) and HCl after 30 seconds?

1) No reaction
2) Bubbles of gas are produced
3) The temperature of the test tube increases
4) The color of the solution changes

Answer 1

Upon adding zinc to hydrochloric acid, bubbles of hydrogen gas are produced, and the temperature of the test tube increases, indicating a chemical reaction.

Step-by-step explanation:

When small pieces of zinc (Zn) are placed in a test tube with 3 ml of 1 M hydrochloric acid (HCl), a chemical reaction occurs. This reaction between zinc and hydrochloric acid produces zinc chloride (ZnCl₂) and hydrogen gas (H₂).

The balanced chemical equation for the reaction is:

Zn(s) + 2 HCl(aq) → ZnCl₂(aq) + H₂(g)

Within 30 seconds of adding zinc to hydrochloric acid, you would observe that bubbles of gas are produced, which indicates the formation of hydrogen gas. Additionally, you might feel an increase in the temperature of the test tube, signifying that the reaction is exothermic (releasing heat).