The flow-chart descriptions suggest Solid P is copper, Gas Q is oxygen, Red-brown gas U is nitrogen dioxide, and Black residue is copper(II) oxide. Solution S is likely copper sulfate formed by dissolving
in
, and the deep blue Solution T is hydrated copper(II) sulfate. Solution V could be a dilute copper sulfate solution.
The substances mentioned in the flow-chart can be identified as follows:
- Solid P likely represents copper (Cu) since heating produces a colorless gas (Q) which relights a glowing splint, indicative of oxygen (
). - Gas Q is oxygen (
). - Red-brown gas U is nitrogen dioxide (
). - Black residue is likely copper(II) oxide (
). - Solution S is formed by dissolving the black residue (copper(II) oxide,
) in sulfuric acid (
) to produce a blue solution which suggests the formation of copper(II) sulfate (
). - The deep blue solution T signifies the presence of hydrated copper(II) sulfate (
·
). - Solution V could be a dilute sulfuric acid solution with traces of copper sulfate.
The equations for the formation:
(s) +
(
) →
(
) +
(l)- To form the deep blue hydrated copper(II) sulfate, the anhydrous CuSO4 usually absorbs water from the air or through hydration process:
(s) +
(l) →
·
(s) - As for solution V, the specific equation would depend on the exact components, but if it involves dilution, no chemical reaction equation is needed, only specification of dilution.
- Upon heating, nitrogen dioxide reacts with sulfur to form sulfur dioxide and is given by:
(g) + S (s) →
(g) +
(g)
Therefore, based on the observations made in the question, including the required heating and color changes, we can infer the identity of the substances as well as suggest possible reactions. Note that several steps refer to laboratory practices that imply no reactions such as dissolving, observing color changes, and recording experiments.