Reaction of copper with acids.
1. Drop some copper fillings into a test tube of dilute hydrochloric acid. Describe what happens/observed.
2. Drop some copper fillings into a test tube containing dilute nitric acid.What happens/observed. Write an equation to explain the reaction.
1. When copper fillings are dropped into a test tube of dilute hydrochloric acid, the copper reacts with the acid, producing bubbles of hydrogen gas and a blue-green solution of copper(II) chloride. This reaction is observed by the formation of effervescence and the change in color of the solution.
2. When copper fillings are dropped into a test tube containing dilute nitric acid, the copper reacts with the acid, producing brown fumes of nitrogen dioxide and a blue solution of copper(II) nitrate. This reaction is observed by the formation of brownish gas and the change in color of the solution.
The equation for the reaction between copper and dilute nitric acid is:
Cu + 4HNO3 -> Cu(NO3)2 + 2NO2 + 2H2O
1. When copper fillings are dropped into a test tube of dilute hydrochloric acid (HCl), a chemical reaction occurs. The copper reacts with the acid, resulting in the formation of bubbles of hydrogen gas (H2). The reaction can be observed by the effervescence or bubbling that takes place.
The equation for the reaction between copper and hydrochloric acid is as follows:
Cu + 2HCl → CuCl2 + H2
In this equation, Cu represents copper, HCl represents hydrochloric acid, CuCl2 represents copper(II) chloride, and H2 represents hydrogen gas.
2. Similarly, when copper fillings are dropped into a test tube containing dilute nitric acid (HNO3), a different chemical reaction takes place. The copper reacts with the nitric acid, resulting in the formation of nitrogen dioxide gas (NO2), brown fumes, and a blue solution of copper(II) nitrate (Cu(NO3)2).
The equation for the reaction between copper and nitric acid is as follows:
3Cu + 8HNO3 → 3Cu(NO3)2 + 4H2O + 2NO2
In this equation, Cu represents copper, HNO3 represents nitric acid, Cu(NO3)2 represents copper(II) nitrate, H2O represents water, and NO2 represents nitrogen dioxide gas.