calcium oxide and nitric acid react. at the start of the reaction, some universal indicator is added. suggest how the colour changes throughout the reaction.
When calcium oxide reacts with nitric acid, it produces calcium nitrate and water. The reaction is as follows:
CaO + 2HNO3 → Ca(NO3)2 + H2O
The addition of universal indicator at the start of the reaction will give a green color to the solution as the indicator will be in its neutral state. As the reaction progresses, the solution will turn from green to yellow as the acid begins to neutralize the basic calcium oxide. As the reaction reaches completion, the solution will turn red, indicating that all the acid has been used up and the solution is acidic due to the formation of calcium nitrate.
Therefore, the color changes throughout the reaction would be green → yellow → red.
When calcium oxide (CaO) reacts with nitric acid (HNO3), a neutralization reaction occurs, forming calcium nitrate (Ca(NO3)2) and water (H2O). The reaction can be represented by the following balanced equation:
CaO + 2HNO3 -> Ca(NO3)2 + H2O
To understand how the color changes throughout the reaction, we need to consider the properties of the reactants and products, as well as the behavior of the universal indicator.
The universal indicator is a pH indicator that changes color based on the pH of the solution. It contains a mix of various indicators, and its color changes can indicate the approximate pH value of the solution.
At the start of the reaction, when calcium oxide and nitric acid are mixed, the solution will be acidic due to the presence of nitric acid. Universal indicator added to an acidic solution typically turns red or pink.
As the reaction progresses, calcium oxide, which is a base, reacts with nitric acid, a strong acid, resulting in the formation of calcium nitrate, which is a neutral compound. As a result, the solution gradually becomes neutral.
Towards the end of the reaction, when all the acid has been neutralized and the solution becomes neutral, the color of the universal indicator will usually turn green to indicate this neutral pH.
It's important to note that the exact color changes may vary depending on the concentration of the reactants and the specific universal indicator used. Nonetheless, the general trend involves a shift from red/pink (acidic) to green (neutral) as the reaction proceeds.