Carbon disulfide, a poisonous, flammable liquid, is an excellent solvent for phosphorus, sulfur, and some other nonmetals. A kinetic study of its gaseous decomposition reveals these data: Experiment Initial [CS2] (mol/L) Initial Rate (mol/L·s) 1 0.100 2.7 × 10−7 2 0.080 2.2 × 10−7 3 0.055 1.5 × 10−7 4 0.044 1.2 × 10−7 (a) Choose the rate law for the decomposition of CS2

Respuesta :

Answer:

Rate law: = [tex]k[CS_2]^1[/tex]

Explanation:

Given:

t               [tex][CS_2][/tex]

0.100            [tex]2.7 \times 10^{-7}[/tex]

0.080          [tex]2.2 \times 10^{-7}[/tex]

0.055         [tex]1.5\times 10^{-7}[/tex]

0.044         [tex]1.2\times 10^{-7}[/tex]

Rate law for the given reaction: [tex]k[CS_2]^n[/tex]

Where, n is the order of the reaction.

Divide rate 1 with rate 3

[tex]\frac{0.100}{0.055} =\frac{k[CS_2 (1)]^n}{k[CS_2 (3)]^n} \\\frac{0.100}{0.055} =\frac{k[2.7 \times 10^{-7}]^n}{k[1.5\times 10^{-7}]^n}\\1.81=[1.8]^n\\ n=1[/tex]

So, rate law = [tex]k[CS_2]^1[/tex]

Answer:

[tex]r=-3.73x10^{5}s^{-1} [CS_2][/tex]

Explanation:

Hello,

In this case, a linealization helps to choose the rate law for the decomposition of CS₂ as it is generalized via:

[tex]r=-k[CS_2]^{n}[/tex]

Whereas [tex]n[/tex] accounts for the order of reaction, which could be computed by linealizing the given data using the following procedure:

[tex]-ln(r)=ln(k[CS_2]^{n})\\-ln(r)=ln(k)+ln([CS_2]^{n})\\-ln(r)=ln(k)+n*ln([CS_2])[/tex]

Therefore, on the attached picture you will find the graph and the lineal equation wherein the slope is the order of the reaction and the y-axis intercept the natural logarithm of the rate constant. In such a way, the order of reaction is 1 and the rate constant is:

[tex]ln(k)=12.83\\k=exp(12.83)\\k=3.73x10^{5}s^{-1}[/tex]

Best regards.