Formation of a New Substance Test Review

A student had a beaker with a small amount of baking soda. The student added a few drops of pickle juice to the baking soda and observed fizzing and bubbling. Based on observation, which of these can the student conclude?

• A chemical reaction produced a solid.

• No chemical reaction took place

• Only physical change happened

• A chemical reaction produced a gas.

Two liquids are mixed together. Which of the following does NOT identify the formation of a new substance?

• A gas is produced.

• One liquid dissolves into the other.

• The temperature changes.

• A solid (precipitate) is formed.

Flour, sugar, cocoa, oil, and eggs are mixed together and placed in the oven to make brownies. When the brownies are removed from the oven, they no longer look like the original ingredients. Which of the following describes why the ingredients changed?

• A biological change occurred.

• No change occurred.

• A physical change occurred.

• A chemical change occurred.

When vinegar and baking soda are combined, bubbles and foam are produced.

What evidence demonstrates that a chemical change has occurred?

• A color change occurs.

• A gas is formed.

• A solid is dissolved.

• A precipitate is formed.

After an investigation, students were disposing of left over substances. One student poured all of the liquids down the sink drain. A few seconds later, a white cloud formed above the sink and the student’s eyes began to burn. Which statement accurately describes what caused this occurrence?

• The student did not wait two minutes in between pouring each liquid down the drain.

• The student did not allow water to run in the sink after pouring each liquid down the drain.

• A physical change occurred resulting in the formation of a new substance

• A chemical change occurred resulting in the formation of a new substance.

A student mixes a solid with a liquid in a beaker. Which of the following describes a chemical change?

• The liquid begins to heat up and a gas is formed.

• The solid dissolves into the liquid.

• The solid falls to the bottom of the beaker.

• Nothing happens.

Which of the following is an example of a physical change?

• combustion of wood(burning)

• boiling of water

• corrosion (like rusting) of copper

• rusting of steel

Which of the following best describes a change in iron caused by a chemical reaction?

• An iron nail looks shiny and silvery.

• An iron nail rubbed with a magnet attracts iron powder.

• An iron wire left outside turns a rusty orange/brownish color.

• An iron wire attached to a battery becomes hot.

Which of these is an example of a chemical reaction?

• A pot of water boiling

• An iron nail rusting

• Corn being ground

• Sugar dissolving in tea

A drain cleaner consists of sodium hydroxide and aluminum. When the drain cleaner is added to water, bubbles of hydrogen are produced, and the solution becomes very hot. Which of these best describes what happens to form the bubbles when the cleaner is added to water?

• A chemical reaction

• Condensation

• A physical change

• Evaporation