Heat is transferred directly from a heat reservoir at 200 C to another heat reservoir at 5C. If the amount of heat transferred i
s 100kJ, what is the total entropy change as a result of this process? Draw a schematic to represent the heat exchange
1 answer:
Answer:
ΔS=0.148 KJ/K
Explanation:
Given that
Q = 100 KJ
T₁=200°C
T₁=200+273 = 437 K
T₂=5°C
T₂=5 + 273 = 278 K
Reservoir 1 is rejecting heat that is why it taken as negative while the reservoir 2 is gaining the heat that is why it is taken as positive.
So the total change in entropy given as
ΔS= - Q/T₁ + Q/T₂
ΔS= - 100/473 + 100/278 KJ/K
ΔS=0.148 KJ/K
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Answer:
Explanation:
From the given information:
mass of silver chloride AgCl = 11.89 g
molar mass of AgCl = 143.37 g/mol
We know that:
number of moles = mass/molar mass
∴
number of moles of AgCl = 11.89 g/ 143.37 g/mol
number of moles of AgCl = 0.0829 mol
The chemical equation for the mineral called trona is:
when being reacted with hydrochloric acid, we have:
One mole of NaCl formed from one mole of trona sample = 0.0829 moles of AgCl
i.e. 0.0829 moles of NaCl can be formed from AgCl
mass of trona sample = number of moles × molar mass
mass of trona sample = 0.0829 × 226
mass of trona sample = 18.735 g
The mass in the percentage of NaHCO₃ = mass of NaHCO₃/ mass of trona
The mass in the percentage of NaHCO₃ = 6.93/18.735
The mass in the percentage of NaHCO₃ = 0.36989
The mass in the percentage of NaHCO₃ = 36.99%
Nonetheless, a 6.78 g samples manufactured from sodium carbonate in pure 100%
∴
6.78 g sample manufactured from Na₂CO₃ is purer.