Acids, alkalis and titrations：练习题

According to the syllabus, which ion is primarily responsible for the properties of an acidic aqueous solution?

Methyl orange is added to a beaker containing dilute hydrochloric acid. Sodium hydroxide solution is then added dropwise until the sodium hydroxide is in excess. What color change is observed in the beaker?

To ensure the highest accuracy in a titration, which of the following describes the correct procedure for preparing the burette before filling it with the standard acid solution?

What is the color of phenolphthalein indicator when it is added to a solution with a pH of 12?

During an acid-alkali titration, which piece of apparatus should be used to accurately measure and transfer exactly \(25.0 \text{ cm}^3\) of the alkali into the conical flask?

Identify the color of phenolphthalein indicator when it is added to a solution with a pH of 12.

In an acid-alkali titration, describe the color change of methyl orange when the solution in the conical flask changes from alkaline to acidic at the end point.

A student records the initial and final burette readings as shown in the provided diagrams. Determine the total volume of acid added during this titration run.

a) Acids are a source of specific ions in aqueous solution. State the formula of the ion that is present in all aqueous acids.

b) A student tests a solution with two different indicators. State the color of the solution if it is strongly acidic (pH 1-2) when using:
(i) Litmus paper
(ii) Methyl orange

c) Complete the word equation for the neutralization reaction between dilute sulfuric acid and potassium hydroxide:
\(\text{sulfuric acid} + \text{potassium hydroxide} \rightarrow\) ________ + ________

A student is asked to prepare a pure, dry sample of hydrated copper(II) sulfate crystals starting from insoluble copper(II) oxide and dilute sulfuric acid.

a) Describe the steps the student should take to ensure that all the sulfuric acid has reacted.
b) How should the student remove the unreacted copper(II) oxide from the mixture?
c) Describe the process of obtaining large, pure crystals from the resulting solution, explaining why the solution should not be evaporated to dryness.