In this redox reaction, the Cu goes from oxidation state of (0) to (+2), therefore it oxidises. N in HNO₃ goes from oxidation state of (+5) to N in NO with oxidation state of (+2) and becomes reduced.
Cu acts as the reducing reagent and HNO₃ is the oxidising agent.
oxidation half reaction
Cu ---> Cu²⁺ + 2e --1)
reduction half reaction
4H⁺ + 3e + NO₃⁻ ---> NO + 2H₂O --2)
to balance the number of electrons , 1) x3 and 2) x2
3Cu ---> 3Cu²⁺ + 6e
8H⁺ + 6e + 2NO₃⁻ ---> 2NO + 4H₂O
add the 2 equations
3Cu + 8H⁺ + 2NO₃⁻ ---> 3Cu²⁺ + 2NO + 4H₂O
add 6 nitrate ions to both sides to add up to 8 and form acid with 8H⁺ ions
3Cu + 8HNO₃ ---> 3Cu(NO₃)₂ + 2NO + 4H₂O
Balanced equation for the redox reaction is as follows;
3Cu(s) + 8HNO₃(aq) → 3Cu(NO₃)₂(aq) + 2NO(g) + 4H₂O<span>(l)
NO has a coefficient of 2
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Answer:
i guess its example of observation
Answer:
The correct answer is: d. The pKa of the chosen buffer should be close to the optimal pH for the biochemical reaction.
Explanation:
The buffer resist or maintain the change in pH in case of Acid or basic addition to the solution. The buffer capacity should be within one or two pH units when compared to the optimal pH.
Thus it is important to select a buffer with pKa close to the optimum pH of the reaction because the ability for the buffer to maintain the pH is is great at the pH close to pKa.
Answer
_2 HNO₃ + 1 Mg(OH)₂ → 1 Mg(NO₃)₂ + 2 H₂O
Explanation
Given:
______HNO3 + Mg(OH)2 ------>
Solution:
Note that the reaction between an acid and a base will give salt and water only.
Hence the complete reaction of the given equation is:
___HNO₃ + Mg(OH)₂ → Mg(NO₃)₂ + H₂O
To get the balanced equation for the acid-base reaction, 2 moles of HNO₃ will react with 1 mole of Mg(OH)₂ to produced 1 mole of Mg(NO₃)₂ and 2 moles of H₂O.
Therefore, the complete and balanced equation for the given acid-base reaction is:
_2 HNO₃ + 1 Mg(OH)₂ → 1 Mg(NO₃)₂ + 2 H₂O
Answer: petroleum
because it is a fossil fuel like coal, and natural gas.
