Ethan makes the table below to record his observations when mixing baking soda and vinegar in a beaker. Ethan claims that a chem
ical change has occurred. Which statement provides the BEST evidence to support his claim?
2 answers:
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Answer:
The temperature of the Nitrogen after throttling is
Explanation:
From the question we are told that
The temperature is
The pressure is
The pressure after being
Generally from the first law of thermodynamics we have that
Here is the change internal energy which is mathematically represented as
Here is the specific heat of the gas at constant pressure
is the change kinetic energy which is negligible
Q is the thermal energy which is Zero for an adiabatic process
W is the work done and the value is zero given that the gas was throttled adiabatically
So
=>
=>
=>
Answer:
The option closest to the percentage yield is option;
d. 81.1
Explanation:
The given chemical equation of the reaction is presented as follows;
CaO (s) + H₂O (l) → Ca(OH)₂
The mass of CaO in the experiment, m = 2.00 g
The volume of water with which the CaO was reacted = Excess volume of water
Number of moles = Mass/(Molar mass)
The mass of Ca(OH)₂ recovered, actual yield = 2.14 g
The molar mass of CaO = 56.0774 g/mol
The number of moles of CaO in the reaction, n₁ = 2.00 g/(56.0774 g/mol ≈ 0.036 moles
The molar mass of Ca(OH)₂ = 74.093 g/mol
The number of moles of Ca(OH)₂ in the reaction, n₂ = 2.14 g/(74.093 g/mol) ≈ 0.029 moles
From the given chemical reaction, one mole of CaO reacts with one mole of H₂O to produce one mole of Ca(OH)₂
Therefore, 0.036 moles of CaO will produce 0.036 moles of Ca(OH)₂
Mass = Number of moles × Molar mass
The mass of 0.036 moles of Ca(OH)₂ ≈ 0.036 moles × 74.093 g/mol = 2.667348 grams
∴ The theoretical yield of Ca(OH)₂ = 2.667348 grams
The percentage yield = (2.14 g)/(2.667348 grams) × 100 = 80.23%
Therefore, the option which is closest is option d. 81.1.