Answer:
a. C: +3 ; b. N: +5 ; c. S:+6 ; d. C: +4; e. Mn: +7 ; f. Cr: +6.
Explanation:
Global charges in molecules is 0
You sum all the oxidation states to determine the oxidation state for the compound.
Na₂C₂O₄ → Sodium oxalate → Global charge: 0
Oxidation state for C: +3
HNO₃ → Nitric acid → Global charge: 0
Oxidation state for N: +5
H₂SO₄ → Sulfuric acid → Global charge: 0
Oxidation state for S: +6
HCO₃⁻ → Bicarbonate → Global charge: -1, this is an anion
Oxidation state for C: +4
KMnO₄ → Potassium permanganate → Global charge: 0
Oxidation state for Mn: +7
Cr₂O₇⁻ → Anion dichromate → Global charge: -2
Oxidation state for Cr: +6
Answer:
(a) The anode electrode which comprises the zinc electrode being placed in a water solution with low oxygen concentration.
(b) Cathodic reaction is:
⇒ 
Anodic reaction is:
⇒
Explanation:
In the given problem, we have an oxygen-concentration cell consisting of two zinc electrodes. One is immersed in a water solution with a low oxygen concentration and the other in a water solution with a high oxygen concentration. The zinc electrodes are connected by an external copper wire.
(a) Which electrode will corrode?
The electrode that will corrode is the anode electrode which comprises the zinc electrode being placed in a water solution with low oxygen concentration.
(b) Write half-cell reactions for the anodic reaction and the cathodic reaction.
Cathodic reaction is:
⇒ 
Anodic reaction is:
⇒
The volume of the granite piece in Cm³ is 12.2 cm³
<u><em>calculation</em></u>
volume of granite = (volume of cylinder after placing granite - volume of cylinder before placing granite
= 37.2 ml - 25.0 ml = 12.2 ml
convert ml to Cm³
that is 1 ml = 1 cm³
12.2 ml = ? cm³
<em>by cross multiplication</em>
=(12.2 ml x 1 cm³) / 1 ml = 12.2 cm³
Answer:
chuma ya ndoshi.............
Explanation:
.
kwenda ukalale .............