The thermochemical equation is the chemical equation including the net change of enthalpy (heat).
The chemical equation for the decomposition of methanol to form methane and oxygen is:
2CH3OH --> 2CH4 + O2
The thermochemical equation is:
2CH3OH ---> 2CH4 + O2 - 252.8 kJ
Note that the heat is placed as negative at the right side because it is absorbed during the decomposition, so the environment will have 252.8 kJ less per each mole of O2 produced.
You can equivalently write:
2CH3OH + 252.8 kJ --> 2CH4 + O2
Answer:
0.550
Explanation:
The absorbance (A) of a substance depends on its concentration (c) according to Beer-Lambert law.
A = ε . <em>l</em> . c
where,
ε: absorptivity of the species
<em>l</em>: optical path length
A 45 mM phosphate solution (solution A) had an absorbance of 1.012.
A = ε . <em>l</em> . c
1.012 = ε . <em>l</em> . 45 mM
ε . <em>l</em> = 0.022 mM⁻¹
We can find the concentration of the second solution using the dilution rule.
C₁ . V₁ = C₂ . V₂
45mM . 11mL = C₂ . 20.0 mL
C₂ = 25 mM
The absorbance of the second solution is:
A = (ε . <em>l</em> ). c
A = (0.022 mM⁻¹) . 25 mM = 0.55 (rounding off to 3 significant figures = 0.550)
Answer:
C. ways radiation is transferred into and through Earth's atmosphere
Explanation:
