Balancing chemistry equations
1 answer:
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Answer:
(a) Cu²⁺ +2e⁻ ⇌ Cu
(c) 0.07 V
Explanation:
(a) Cu half-reaction
Cu²⁺ + 2e⁻ ⇌ Cu
(c) Cell voltage
The standard reduction potentials for the half-reactions are+
<u> E°/V </u>
Cu²⁺ + 2e⁻ ⇌ Cu; 0.34
Hg₂Cl₂ + 2e⁻ ⇌ 2Hg + 2Cl⁻; 0.241
The equation for the cell reaction is
E°/V
Cu²⁺(0.1 mol·L⁻¹) + 2e⁻ ⇌ Cu; 0.34
<u>2Hg + 2Cl⁻ ⇌ Hg₂Cl₂ + 2e⁻; </u> <u>-0.241 </u>
Cu²⁺(0.1 mol·L⁻¹) + 2Hg + 2Cl⁻ ⇌ Cu + Hg₂Cl₂; 0.10
The concentration is not 1 mol·L⁻¹, so we must use the Nernst equation
(ii) Calculations:
T = 25 + 273.15 = 298.15 K
Explanation:
First, we will calculate the molar mass of as follows.
Molar mass of =
= 78 g/mol
So, when 2 mol of burns, then heat produced = 6542 KJ
Hence, this means that 2 molecules of are equal to
of
burns, heat produced = 6542 KJ
Therefore, heat produced by burning 5.5 g of =
= 228.97 kJ
= 228970 J (as 1 kJ = 1000 J)
It if given that for water, m = 5691 g
And, we know that specific heat capacity of water is 4.186
.
As, Q =
228970 J =
Thus, we can conclude that the final temperature of the water is .