Group VII properties：練習問題

What is the appearance of bromine at room temperature and pressure (r.t.p.)?

Which statement correctly describes the trend in properties of the Group VII halogens as the atomic number increases?

In Experiment 1, aqueous chlorine is added to aqueous potassium bromide.
In Experiment 2, aqueous bromine is added to aqueous potassium iodide.
Which row correctly identifies the final color of the solutions?

A student adds aqueous bromine to a solution of potassium iodide.
Which observation would be made?

Element X has a proton number of 85. Based on its position in the Periodic Table, which row correctly predicts the properties of element X?

State the appearance (physical state and color) of chlorine at room temperature and pressure.

Predict the reactivity and physical state of astatine at room temperature based on the trends in Group VII.

Explain why bromine can displace iodine from an aqueous solution of potassium iodide, referencing the reactivity of halogens.

The halogens in Group VII show a trend in reactivity that can be demonstrated through displacement reactions.

(a) Describe the observations when aqueous chlorine is added to a solution of potassium iodide.
(b) Write the ionic equation for this reaction, including state symbols.
(c) Explain why no reaction occurs when aqueous bromine is added to a solution of potassium chloride.

A student investigates the properties of three unknown halogens: X, Y, and Z. The following results were recorded:

1. X is a pale yellow-green gas at r.t.p.
2. Y is a red-brown liquid at r.t.p.
3. When aqueous X is added to a solution containing Z- ions, a grey-black solid is formed.

(a) Identify halogens X, Y, and Z.
(b) Arrange X, Y, and Z in order of increasing density.
(c) Explain the trend in reactivity for Group VII elements by referring to their atomic size and the ability to attract an incoming electron.