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SashulF [63]
3 years ago
12

1. An electric power plant uses energy from burning coal to generate steam at 450 °C. The plant is cooled by 20 °C water

Chemistry
1 answer:
kap26 [50]3 years ago
6 0

Answer:

Explanation:

Efficiency of the electric power plant is e=1-\frac{T_{2}}{T_{1}}

Here Temperature of hot source T_{1} = 450^{o}C=450+273=723 K

and Temperature of sink T_{1} = 20^{o}C=20+273=293 K

Hence the efficiency is  e=1-\frac{293}{723}=0.5947=59.47%

Now another formula for thermal efficiency Is

e_{therm}=\frac{Q_{1}-Q_{2}}{Q_{1}}=\frac{W}{Q_{1}}

Here QI is the of heat taken from source 100 MJ ; Q2 of heat transferred to the sink (river) to be found

W is the of work done and W = QI -Q2

Hence Frome_{therm}=\frac{Q_{1}-Q_{2}}{Q_{1}}=\frac{W}{Q_{1}}

W=e(Q_{1})=(0.5947)(100)=59.47MJ

Hence the of heat transferred to the river Is Q_{2} -W = (100 -59.47=40.53

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6 0
1 year ago
A manganese electrode was oxidized electrically. If the mass of the electrode decreased by 225 mg during the passage of 1580 cou
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Answer:

<u>Oxidation state of Mn = +4</u>

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i.e Z = \frac{m}{Q} = \frac{0.225g}{1580C} = 0.0001424 g/C

But Equivalent weight, E = atomic mass ÷ valency  = Z × 96,485

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