In this lab, one piece of evidence that showed a double displacement reaction occurred was when a solid (precipitate) was formed. This is evident in the reaction between sodium sulphate and barium chloride. One of the products in this reaction was barium sulphate which is a white precipitate in an aqueous solution. This precipitate is definite evidence of a chemical reaction. Another characteristic that showed a double displacement reaction occurred was when a gas was produced. This is evident in the reaction between sodium carbonate and hydrochloric acid. One of the products is hydrogen carbonate which decomposes to carbon dioxide and water. Carbon dioxide is a colourless gas that indicated a chemical reaction occurred. Another piece of evidence …show more content…
After performing the lab, it is evident that one of the indicators of a double displacement reaction is the formation of a precipitate in an aqueous solution. This was seen through two of the reactions performed in this lab; sodium sulphate with barium chloride and lead (II) nitrate with potassium iodide. In the reaction between lead (II) nitrate and potassium iodide, both of the solutions were transparent liquids before they were mixed. However, after the solutions were mixed, a dark yellow precipitate formed within the aqueous solution. This indicated a chemical reaction occurred in this double displacement reaction. Another property that indicates a double displacement reaction occurred is the formation of gas. This was seen through three of the reactions performed in this lab; sodium carbonate with hydrochloric acid, sodium carbonate with sulphuric acid, and sodium hydroxide with ammonium chloride. In the sodium hydroxide and ammonium chloride reaction, when the two solutions are mixed, bubbles began to form rapidly. This clearly indicated that a gas was released when the reactants were mixed. Lastly, a property that indicates a double displacement reaction occurred is a temperature change. This is seen through the reaction between sodium hydroxide and sulphuric acid. In this reaction, the acid and the base combined to form a colourless solution. However, it was observed that the reaction released heat indicating a chemical reaction occurred. After observing the chemical equation, the anion from the acid and the cation from the base combined to form a salt and water, a neutralization reaction. Thus, it can be concluded a neutralization reaction is an indicator of a double displacement reaction. The property that indicated a double displacement reaction did not occur was when the products of