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How would you remove unreacted copper oxide from solution?

A. Filtration

B. Distillation

C. Evaporation

D. Decantation

Answer Explanation:

A) Filtration (Correct Answer): Filtration is a commonly used method to separate solid particles, such as unreacted copper oxide, from a liquid solution. The solution containing the dissolved copper sulfate can pass through the filter paper, while the solid copper oxide particles are retained on the filter.

B) Distillation: Distillation is a process used to separate components of a mixture based on differences in their boiling points. It is not typically used to separate solid particles from a liquid solution.

C) Evaporation: Evaporation involves heating the solution to allow the solvent (water) to vaporize, leaving behind the solute (copper sulfate) as solid crystals. While evaporation can concentrate the solution, it does not effectively remove solid particles like unreacted copper oxide.

D) Decantation: Decantation involves pouring off the liquid portion of a mixture, leaving the solid behind. While it can be used to separate solid and liquid phases, it may not effectively separate fine solid particles like unreacted copper oxide from the solution. Filtration would be a more suitable method for this purpose.

Therefore, the Correct Answer is A.

More Questions on TEAS 7 Science

  • Q #1: What ions make ammonia solution alkaline?

    A. Cl- ions

    B. H+ ions

    C. Na+ ions

    D. OH- ions

    Answer Explanation

    A) Cl- ions: Chloride ions (Cl-) are typically found in salts and do not contribute directly to the alkalinity of ammonia solution.

    B) H+ ions: Hydrogen ions (H+) typically characterize acidic solutions, not alkaline solutions. Ammonia solution doesn't contain H+ ions.

    C) Na+ ions: Sodium ions (Na+) are typically found in salts and do not contribute directly to the alkalinity of ammonia solution.

    D) OH- ions (Correct Answer): Ammonia solution becomes alkaline due to the presence of hydroxide ions (OH-). Ammonia (NH3) reacts with water to form ammonium ions (NH4+) and hydroxide ions (OH-), increasing the concentration of OH- ions and making the solution alkaline.

  • Q #2: When acids and bases react together, we call this a:

    A. Neutralization reaction.

    B. Decomposition reaction.

    C. Synthesis reaction.

    D. Redox reaction.

    Answer Explanation

    A. Neutralization reaction. (Correct Answer): When acids and bases react, they undergo a neutralization reaction, resulting in the formation of water and a salt. In this reaction, the acidic properties of the acid are neutralized by the basic properties of the base.

    B. Decomposition reaction: A decomposition reaction involves the breakdown of a compound into smaller substances. It does not typically describe the reaction between acids and bases.

    C. Synthesis reaction: A synthesis reaction involves the formation of a compound from simpler substances. It does not typically describe the reaction between acids and bases.

    D. Redox reaction: A redox reaction involves the transfer of electrons between reactants. While redox reactions can occur in certain acid-base reactions, they are not specific to the reaction between acids and bases. The typical reaction between acids and bases involves proton transfer rather than electron transfer. Therefore, "neutralization reaction" is a more specific and accurate term for this type of reaction.

  • Q #3: What ions make ethanoic acid acidic?

    A. H+ ions

    B. OH- ions

    C. Na+ ions

    D. Cl- ions

    Answer Explanation

    A) H+ ions (Correct Answer): Ethanoic acid (acetic acid) is acidic because it donates protons (H+) in solution, leading to the formation of hydronium ions (H3O+). This process characterizes acids.

     

    B) OH- ions: Hydroxide ions (OH-) typically characterize bases, not acids. Ethanoic acid doesn't contain hydroxide ions.

     

    C) Na+ ions: Sodium ions (Na+) are not responsible for the acidity of ethanoic acid. Na+ ions are typically found in salts and do not contribute to acidity.

     

    D) Cl- ions: Chloride ions (Cl-) are not responsible for the acidity of ethanoic acid. Cl- ions are typically found in salts and do not contribute to acidity.