Answer: AZ is the insoluble choice.
Explanation:
Z is an anion of a weak electronegative element. Hence, it bounds lightly with the highly electropositive cation A to form AZ.
AZ is not as ionic as AX, AY, BX, BY and BZ, so it is insoluble in water and yields precipitate on reaction with the salt of a weaker metal.
Answer : Hypothesis.
Explanation : Hypothesis is defined as the supposition or proposed explanation which can be made on the basis of limited available evidence as a starting point for further investigation. Here, in this question the proposed explanation for the changing colors of the sky is an example of a hypothesis.
A hypothesis has to be supported with scientific experiments which are reproducible by several experiments and test results have to be valid to be called as a scientific theory.
1500 cm^3 ; 1 mL equals 1 cm^3
Answer:
SO₃²⁻ is the reducing agent and Cr₂O₇²⁻ is the oxidizing agent.
Explanation:
Oxidation reaction:
3SO₃²⁻ (aq) + 3H₂O (l) → 3SO₄²⁻ (aq) + 6H⁺ (aq) + 6e⁻
Reduction reaction:
Cr₂O₇²⁻ (aq) + 14H⁺ (aq) + 6e⁻ → 2Cr ³⁺ (aq) + 7H₂O (l)
Now, adding the oxidation and the reduction reactions we get the full net reaction:
Cr₂O₇²⁻ (aq) + 3SO₃²⁻ (aq) + 8H⁺ (aq) → 2Cr ³⁺ (aq) + 3SO₄²⁻ (aq) + 4H₂O(l)
Since, the S in SO₃²⁻, present in the +4 oxidation state is oxidized to +6 oxidation state in SO₄²⁻, by the loss of 2e⁻.
<u>Therefore, SO₃²⁻ is the reducing agent. </u>
And, the Cr in Cr₂O₇²⁻, present in the +6 oxidation state is getting reduced to +3 oxidation state, Cr ³⁺, by the gain of 6e⁻.
<u>Therefore, Cr₂O₇²⁻ is the oxidizing agent.</u>
