Introduction to Chemical Reactions Answers

Which is evidence that a chemical reaction has likely occurred?

When vinegar and baking soda react, the mixture becomes cold to the touch and a gas and a new liquid substance are formed.

Pedro wants to create a chemical reaction between oil and water. He adds oil to a beaker of water and notices that the liquids do not mix. He then shakes the beaker and the drops of oil become suspended through the water for a few moments before returning to their separate layers.

When liquid silver nitrate and liquid sodium chloride are combined, solid silver chloride forms along with a new liquid, sodium nitrate. Which substance represents the precipitate?

Cherylanne mixes together Chemical A and Chemical B in a test tube, forming Chemical C. The mixture instantly turns cool to the touch. She then adds Chemical D, and the reaction becomes hot and explodes.

A Venn diagram is used to compare and contrast different topics. The items that are unique to each topic are represented in the separate sections of the circles, and the items that are common to both topics are represented in the center overlapping sections. Harlow creates this Venn diagram comparing and contrasting endothermic and exothermic processes.

Which of these most likely represents a chemical change?

What must occur in order for a chemical reaction to be specifically classified as endothermic instead of exothermic?

Which is an example of a chemical reaction?

Which best explains why a firework being ignited is an example of an exothermic reaction and not an endothermic reaction?