/

What is a precipitate?

A. A gas formed during a chemical reaction

B. A liquid formed when two aqueous solutions react

C. A solid formed when two aqueous solutions react

D. A solution formed during a chemical reaction

Answer Explanation:

A) A gas formed during a chemical reaction: While gases can indeed be produced during chemical reactions, a precipitate specifically refers to a solid that forms during a reaction.

B) A liquid formed when two aqueous solutions react: Precipitates are not liquids. They are solids that are formed when certain ions combine to form an insoluble compound.

C) A solid formed when two aqueous solutions react (Correct Answer): A precipitate is indeed a solid substance that forms when two aqueous solutions react and certain ions combine to create an insoluble compound.

D) A solution formed during a chemical reaction: A precipitate is not a solution. It is the solid product that separates out of a solution during a chemical reaction due to its limited solubility.

Therefore, the Correct Answer is C.

More Questions on TEAS 7 Science

  • Q #1: Which acid is needed to make ammonium nitrate?

    A. Sulfuric acid

    B. Hydrochloric acid

    C. Nitric acid

    D. Acetic acid

    Answer Explanation

    A) Sulfuric acid: Sulfuric acid is not used in the production of ammonium nitrate. Although sulfuric acid is a widely used acid in various industries, it is not involved in the synthesis of ammonium nitrate.

    B) Hydrochloric acid: Hydrochloric acid is not used in the production of ammonium nitrate. While it is an important industrial acid, it does not react with ammonia to produce ammonium nitrate.

    C) Nitric acid (Correct Answer): Ammonium nitrate is typically produced by reacting ammonia (NH3) with nitric acid (HNO3). The reaction forms ammonium nitrate (NH4NO3), which is a common fertilizer and explosive compound.

    D) Acetic acid: Acetic acid, commonly known as vinegar, is not used in the production of ammonium nitrate. It is a weak acid and does not react with ammonia to form ammonium nitrate.

  • Q #2: What is produced when an acid reacts with a metal?

    A. Salt and water

    B. Carbon dioxide and water

    C. Oxygen gas and water

    D. Salt and hydrogen

    Answer Explanation

    A) Salt and water: This reaction occurs when an acid reacts with a metal hydroxide or a metal oxide. When metals react with acids, hydrogen gas is typically produced along with a salt, not water.

    B) Carbon dioxide and water: This reaction occurs when an acid reacts with a metal carbonate, not a metal. When carbonates react with acids, carbon dioxide gas is produced along with water and a salt.

    C) Oxygen gas and water: This reaction is not typical when an acid reacts with a metal. Metal reactions with acids usually produce hydrogen gas along with a salt.

    D) Salt and hydrogen (Correct Answer): When an acid reacts with a metal, hydrogen gas is produced along with a salt. The metal displaces hydrogen ions from the acid, forming a salt, while hydrogen gas is released as a byproduct of the reaction.

  • Q #3: What is the Brønsted-Lowry definition of an acid and base?

    A. Acids are electron donors and bases are electron acceptors.

    B. Acids are proton donors and bases are proton acceptors.

    C. Acids are proton acceptors and bases are proton donors.

    D. Acids are compounds that increase the concentration of hydroxide ions in solution and bases are compounds that increase the concentration of hydrogen ions in solution.

    Answer Explanation

    A) Acids are electron donors and bases are electron acceptors: This statement describes the Lewis definition of acids and bases, which focuses on the transfer of electron pairs, rather than the Brønsted-Lowry definition, which involves the transfer of protons.

    B) Acids are proton donors and bases are proton acceptors. (Correct Answer): According to the Brønsted-Lowry definition, an acid is a substance that donates a proton (H+ ion), while a base is a substance that accepts a proton.

    C) Acids are proton acceptors and bases are proton donors: This statement incorrectly describes the roles of acids and bases according to the Brønsted-Lowry definition. Acids donate protons, while bases accept protons.

    D) Acids are compounds that increase the concentration of hydroxide ions in solution and bases are compounds that increase the concentration of hydrogen ions in solution: This statement does not accurately represent the Brønsted-Lowry definition. Acids and bases are defined based on their behavior regarding proton transfer, not changes in ion concentration.