Chemical Reactions

People have used gunpowder as an explosive for hundreds of years. Gunpowder is a mixture of three different substances: potassium nitrate, charcoal, and sulfur. When these substances are burned together, they release a large amount of heat and gas. In the past, gunpowder was used in muskets and cannons, but today, it is mainly used in fireworks.

In this chemical reaction, charcoal is the _________.

• REACTANT

• PRODUCT

Answer explanation

In the chemical reaction involving gunpowder, charcoal is one of the substances that react together with potassium nitrate and sulfur. Therefore, charcoal is classified as a REACTANT.

Tags

NGSS.MS-PS1-2

Gasoline provides the energy that powers many car engines. In an engine, gasoline and oxygen are mixed together and burned, creating carbon dioxide gas and water vapor. This process releases energy that the engine uses to turn the wheels, making the car move.

In this chemical reaction, gasoline is a _______.

• REACTANT

• PRODUCT

Answer explanation

In the chemical reaction described, gasoline is mixed with oxygen and burned, making it a reactant. Reactants are the starting materials in a chemical reaction, while products are the substances formed as a result.

Tags

NGSS.MS-PS1-2

To help relieve pain during a dental visit, a dentist may give a patient nitrous oxide. Nitrous oxide is made in factories by carefully heating ammonium nitrate. At 170°C, ammonium nitrate breaks down and forms a mixture of nitrous oxide gas and water vapor. After the mixture is collected, the water vapor is separated from the nitrous oxide gas.

In this chemical reaction, water is a ___________.

• REACTANT

• PRODUCT

Answer explanation

In the breakdown of ammonium nitrate, nitrous oxide and water vapor are formed. Since water is produced as a result of the reaction, it is classified as a PRODUCT.

Some chemical factories make hydrogen gas (H2) using a process called steam methane reforming. In this process, methane (CH4) combines with steam (H2O) at high temperatures to form a mixture of hydrogen gas and carbon monoxide (CO). This mixture can then be used to make substances like hydrogen fuel and ammonia.

In the chemical reaction described in the passage, which of the following are products?

• methane (CH₄) &

  steam (H₂O)

• hydrogen (H₂) &

  carbon monoxide (CO)

• carbon monoxide (CO) & methane (CH₄)

Answer explanation

In the steam methane reforming process, methane (CH4) and steam (H2O) react to produce hydrogen gas (H2) and carbon monoxide (CO). Therefore, the correct products are hydrogen (H2) and carbon monoxide (CO).

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Your body breaks down food by making stomach acid, which is composed mostly of hydrochloric acid (HCl). If your body makes too much stomach acid, you may suffer from an upset stomach. Antacids like sodium bicarbonate (NaHCO3) can relieve an upset stomach by combining with hydrochloric acid. This combination forms sodium chloride (NaCl), water (H2O), and carbon dioxide (CO2), reducing the amount of acid in the stomach.

In the chemical reaction described in the passage, which of the following are reactants?

• sodium chloride (NaCl) &

  water (H2O)

• hydrochloric acid (HCl) &

  sodium bicarbonate (NaHCO3)

Answer explanation

In the chemical reaction, the reactants are the substances that undergo change. Here, hydrochloric acid (HCl) and sodium bicarbonate (NaHCO3) react to form products, making them the correct reactants.

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Soda-lime glass is the most common type of glass manufactured in the world. The "soda" in soda-lime glass does not come from a soft drink. Instead, it comes from a substance called soda ash (Na2CO3). Soda ash is made using the Solvay process, which was developed in the 1860s. In this process, soda ash and calcium chloride (CaCl2) are made from sodium chloride (NaCl) and calcium carbonate (CaCO3).

In the chemical reaction described in the passage, which of the following are products?

• sodium chloride (NaCl) &

  calcium carbonate (CaCO3)

• calcium chloride (CaCl2) &

  soda ash (Na2CO3)

• calcium carbonate (CaCO3) &

  soda ash (Na2CO3)

Answer explanation

In the Solvay process, sodium chloride (NaCl) and calcium carbonate (CaCO3) react to produce calcium chloride (CaCl2) and soda ash (Na2CO3). Therefore, the correct products are calcium chloride (CaCl2) and soda ash (Na2CO3).

Tags

NGSS.MS-PS1-2

Did you know that glow sticks give off light because of a chemical reaction? A glow stick contains two compounds: hydrogen peroxide (H2O2) and diphenyl oxalate (C14H10O4), which are separated by a barrier inside the glow stick. When you bend a glow stick, the barrier breaks and the substances mix, forming phenol (C6H6O) and carbon dioxide (CO2). The energy released by this reaction makes the glow stick give off colored light.

In the chemical reaction described in the passage, which of the following are reactants?

• hydrogen peroxide (H2O2) &

  diphenyl oxalate (C14H10O4)

• phenol (C6H6O) &

  carbon dioxide (CO2)

• carbon dioxide (CO2) &

  diphenyl oxalate (C14H10O4)

Answer explanation

In the chemical reaction, the reactants are the substances that undergo change. The passage states that hydrogen peroxide (H2O2) and diphenyl oxalate (C14H10O4) mix to produce phenol and carbon dioxide, making them the reactants.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Over 200,000 miles of train tracks have been built in the United States since the early 1800s. Workers who build new train tracks often use a process called thermite welding to connect short pieces of metal track. This type of welding uses thermite powder, which is a mixture of aluminum metal (Al) and ferric oxide (Fe2O3). A worker places the powder between two pieces of track and burns it to form aluminum oxide (Al2O3) and iron metal (Fe). This process releases an enormous amount of energy that melts the two pieces of track together.

In the chemical reaction described in the passage, which of the following are reactants?

• aluminum metal (Al) &

  ferric oxide (Fe2O3)

• aluminum oxide (Al2O3) &

  iron metal (Fe)

Answer explanation

In the thermite welding reaction, the reactants are aluminum metal (Al) and ferric oxide (Fe2O3), as they are the substances that undergo a chemical change to produce aluminum oxide (Al2O3) and iron metal (Fe).

Tags

NGSS.MS-PS1-2

All organisms need energy to live. Many organisms, such as humans and other mammals, obtain energy from food using a process called aerobic respiration. During aerobic respiration, a sugar called glucose (C6H12O6) combines with oxygen (O2), forming carbon dioxide (CO2) and water (H2O). Organisms use the energy released from this process to carry out the functions necessary for life.

Name the reactants from the above passage.

• glucose (C6H12O6) &

  carbon dioxide (CO2)

• glucose (C6H12O6) &

  oxygen (O2)

• carbon dioxide (CO2) &

  water (H2O)

• glucose (C6H12O6) &

  water (H2O)

Answer explanation

The reactants in aerobic respiration are glucose (C6H12O6) and oxygen (O2), as they combine to produce carbon dioxide (CO2) and water (H2O). Therefore, the correct choice is glucose (C6H12O6) & oxygen (O2).

Tags

NGSS.MS-LS1-7

All organisms need energy to live. Many organisms, such as humans and other mammals, obtain energy from food using a process called aerobic respiration. During aerobic respiration, a sugar called glucose (C6H12O6) combines with oxygen (O2), forming carbon dioxide (CO2) and water (H2O). Organisms use the energy released from this process to carry out the functions necessary for life.

Name the products from the above passage.

• glucose (C6H12O6) &

  carbon dioxide (CO2)

• glucose (C6H12O6) &

  oxygen (O2)

• carbon dioxide (CO2) &

  water (H2O)

• glucose (C6H12O6) &

  water (H2O)

Answer explanation

The passage states that during aerobic respiration, glucose combines with oxygen to produce carbon dioxide and water. Therefore, the correct products are carbon dioxide (CO2) and water (H2O).

Tags

NGSS.MS-LS1-7