Reactions Of Metals And Metal Carbonates

The correct answer is CO2 because carbon dioxide is composed of one carbon atom bonded to two oxygen atoms. The chemical formula CO2 represents this composition accurately.

When carbon dioxide gas is passed through limewater, it forms a white precipitate of calcium carbonate, making the limewater cloudy. This is a positive result for the presence of carbon dioxide gas.

The correct answer is H2. Hydrogen gas is composed of two hydrogen atoms bonded together, which is represented by the chemical formula H2.

A lit splint produces a squeaky pop sound when it comes into contact with hydrogen gas. This is because hydrogen gas is highly flammable and reacts explosively with oxygen in the presence of a flame. The reaction produces water vapor and releases energy, causing the characteristic squeaky pop sound. Therefore, a positive result for hydrogen gas can be determined by observing this reaction with a lit splint.

When an acid reacts with a metal, it produces a salt and hydrogen gas. The salt is formed by the combination of the metal cation from the metal and the anion from the acid. The hydrogen gas is released as a byproduct of the reaction. Therefore, the correct answer is "salt, Salt."

When an acid reacts with a metal carbonate, it produces salt, water, and carbon dioxide. In this case, the blank should be filled with "carbon dioxide" or any variation of it, such as "Carbon Dioxide" or "Carbon dioxide" or "carbon Dioxide".

In a chemical reaction, the change of state is not considered an observation. This is because a change of state, such as from a solid to a liquid or a gas, is a physical change rather than a chemical change. Observations in a chemical reaction typically involve changes in color, temperature, odor, or the formation of bubbles (effervescence), which indicate the release of a gas.