Answer:
1) When 6.97 grams of sodium(s) react with excess water(l), 56.0 kJ of energy are evolved.
2) When 10.4 grams of carbon monoxide(g) react with excess water(l), 1.04 kJ of energy are absorbed.
Explanation:
1) The following thermochemical equation is for the reaction of sodium(s) with water(l) to form sodium hydroxide(aq) and hydrogen(g).
2 Na(s) + 2H₂O(l) ⇒ 2NaOH(aq) + H₂(g) ΔH = -369 kJ
The enthalpy of the reaction is negative, which means that 369 kJ of energy are evolved per 2 moles of sodium. The energy evolved for 6.97 g of Na (molar mass 22.98 g/mol) is:
2) The following thermochemical equation is for the reaction of carbon monoxide(g) with water(l) to form carbon dioxide(g) and hydrogen(g).
CO(g) + H₂O(l) ⇒ CO₂(g) + H₂(g) ΔH = 2.80 kJ
The enthalpy of the reaction is positive, which means that 2.80 kJ of energy are absorbed per mole of carbon monoxide. The energy evolved for 10.4 g of CO (molar mass 28.01 g/mol) is:
The correct answer is 0.16138
<u>Solution:</u>
Percentage transmission (%T) of the sample = 15.6
Therefore, Absorbance (A) 2 – log (%T) = 2 – log (15.6) = 0.8069
<u>Use Beer’s law:</u>
A = ε*c*l where ε = molar absorptivity of the solution, c = concentration of the solution, and l = path length of the solution.
Given A = 0.8069 and l = 5.00 cm, we must have
<u>0.8069 = ε*c*(5.00 cm)</u>
ε*c = 0.16138 cm-1
For the next part, assume that ε*c remains constant and we have
A’ = ε*c*l’ where l = 1.00 cm.
Plug in values and write
A’ = (0.16138 cm-1)*(1.00 cm) = 0.16138
The ratio of the light intensity entering the sample to the light intensity exiting the sample at a particular wavelength is defined as the transmittance. Absorption and transmission are two related and different quantities used in spectroscopy. The main difference between absorption and transmission is that absorption measures how much incident light is absorbed as it travels through the material, while transmission measures how much light is transmitted.
Learn more about The absorbance here:-brainly.com/question/14919298
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Answer:
I think that the answer is A.
H2O as it has a relative atomic mass of 18
