1.
Which of the following methods cannot be used to prepare a sample of zinc sulfate?
Correct Answer
D. Adding aqueous zinc nitrate to aqueous sodium sulfate
Explanation
Adding aqueous zinc nitrate to aqueous sodium sulfate cannot be used to prepare a sample of zinc sulfate because this reaction would result in the formation of zinc nitrate and sodium sulfate, not zinc sulfate.
2.
A student adds Universal Indicator to 2 test tubes containing unknown solutions. If the solution in test tube 1 turns purple and the solution in test tube 2 turns green. what are the two solutions likely to be?
Correct Answer
D. Potassium hydroxide / sodium chloride
Explanation
The Universal Indicator changes color based on the pH of a solution. Purple indicates a high pH, while green indicates a neutral pH. Therefore, the solution in test tube 1 is likely to be potassium hydroxide, which is a strong base, while the solution in test tube 2 is likely to be sodium chloride, which is a neutral salt.
3.
Dilute sulfuric acid reacts with magnesium oxide and magnesium carbonate. How are these two reactions alike?
Correct Answer
A. Water is produced.
Explanation
Both reactions involving dilute sulfuric acid and magnesium oxide/magnesium carbonate produce water as a product.
4.
Which of the following is a basic oxide?
Correct Answer
B. Sodium oxide
Explanation
Sodium oxide is a basic oxide because it reacts with water to form a strong base, sodium hydroxide. Basic oxides are typically metal oxides that react with water to form a base, while acidic oxides react with water to form an acid. Carbon monoxide, zinc oxide, and sulfur dioxide are not basic oxides.
5.
Which of the following does produces hydrogen ions in aqueous solutions?
Correct Answer
A. Hydrogen Chloride
Explanation
Hydrogen chloride (HCl) is a strong acid that dissociates in water to produce hydrogen ions (H+) and chloride ions (Cl-). In aqueous solutions, HCl donates a proton to water to form hydronium ions (H3O+), which are equivalent to hydrogen ions. Therefore, hydrogen chloride is the compound that produces hydrogen ions in aqueous solutions.
6.
Which of the following is not a property of an aqueous solution of calcium hydroxide?
Correct Answer
C. It reacts with magnesium to produce hydrogen.
Explanation
An aqueous solution of calcium hydroxide does not react with magnesium to produce hydrogen. This is because calcium hydroxide is a strong base, while magnesium is a less reactive metal. In general, less reactive metals do not readily react with strong bases to produce hydrogen gas. Therefore, this property is not observed in an aqueous solution of calcium hydroxide.
7.
Which of the following is the least soluble in water?
Correct Answer
B. Barium sulfate
Explanation
Barium sulfate is the least soluble in water compared to the other compounds listed. This is because barium sulfate has a low solubility product constant (Ksp), indicating that it does not readily dissociate into its ions in water. As a result, it remains mostly undissolved as a solid in water, making it the least soluble compound among the options given.
8.
Which salt is best prepared by a titration method?
Correct Answer
C. Sodium nitrate
Explanation
Sodium nitrate is best prepared by a titration method because it is a strong oxidizing agent and can react with other substances in a controlled manner. Titration allows for precise measurement of the amount of sodium nitrate needed to react with a specific substance, ensuring accurate and consistent results. Additionally, sodium nitrate is commonly used in titration experiments due to its stability and solubility in water, making it an ideal choice for this method.
9.
Which of the following salts cannot be prepared by a reaction between a dilute acid and a metal?
Correct Answer
D. Copper (II) chloride
Explanation
Copper (II) chloride cannot be prepared by a reaction between a dilute acid and a metal because copper is less reactive than hydrogen. In a reaction between a dilute acid and a metal, hydrogen gas is produced and the metal reacts with the acid to form a salt. However, copper is less reactive than hydrogen, so it does not displace hydrogen from the acid and therefore cannot form copper (II) chloride through this reaction.
10.
Which of the following compounds is a soluble base?
Correct Answer
D. Sodium oxide
Explanation
Sodium oxide is a soluble base because it dissolves in water to form sodium hydroxide, which is a strong base.