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# Using the Arrhenius equation? watch

1. Hi, I'm a little unsure of how to re-arrange the equation below to make K2 the subject...

Q1) Sulfacetamide is known to undergo hydrolysis with a first order rate constant (k1) of 9 × 10-6 s-1 at 120°C (T1=393 K).

Using the following modification of the Arrhenius Equation, calculate the hydrolysis rate constant (k2) at 25°C (T2=298 K).

Arrhenius equation (mod.):
log (k2/k1) = (Ea(T2-T1)) / (2.303 × R × T2 × T1)

note that R = 8.314 J mol-1 K-1 and the activation energy (Ea) is 94 kJ mol-1.

Express your answer in index form, rounding the first box to 1 d.p.

k2 = __ × 10^-- s-1
2. Did you know that log(a/b) = log(a) - log(b)?
Did you know that log(a/b) = log(a) - log(b)?
No I didn't :/

Thanks for that! I think I can do it now
4. Okay, so I got the answer of -5.0497
How do I express that in index form? Sorry such a simple question..but I've gone blank :/
5. Check your working. The rate constant should be positive!

You also know that k2 < k1, as the reaction rate will be slower at a lower temperature.

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