Trini adds 10g of baking soda to 100g of vinegar. The mixture begins to bubble. When the bubbling stops, Trini finds the mass of the resulting mixture. She determines that the mass is 105g.
How do you know that a chemical change has occurred?
Mass was destroyed when vinegar reacted with baking soda.
Mass was destroyed when vinegar reacted with baking soda.
The vinegar evaporated during the experiment.
, , The vinegar evaporated during the experiment.
The substances reacted, producing gas.
The substances reacted, producing gas.
Mixtures always have less mass than their parts.
The correct answer is: The substances reacted, producing gas.
To determine if a chemical change has occurred, we observe certain indicators such as the production of gas, the formation of a precipitate, a change in color, or the release or absorption of heat or light. In this case, the fact that the mixture of vinegar and baking soda produced bubbling indicates that a chemical reaction occurred. The bubbling is a result of the release of carbon dioxide gas when the vinegar (acetic acid) reacts with the baking soda (sodium bicarbonate).
During the reaction, carbon dioxide gas is released, which causes the bubbling. This is evidence of a chemical change because a new substance (carbon dioxide gas) is being produced. The mass of the resulting mixture is 105g because the carbon dioxide gas was released into the surroundings, but this doesn't mean that mass was destroyed. Mass is conserved in chemical reactions, meaning it cannot be created or destroyed, only transformed. In this case, the total mass of the reactants (vinegar and baking soda) is equal to the total mass of the resulting mixture and the gas that was released.