# first order reactionWatch

Thread starter 4 weeks ago
#1
A first order reaction is 38.5% complete in 480 s

(a) Calculate the rate constant.

Use ln ([At]/[A0]) = - k t

k = 1.01 x 10-3 s-1
however l would like to know how you would work it out yourself because on the calculator l get the wrong answer but when l do it on paper l get the right answer
0
4 weeks ago
#2
(Original post by channnnnn)
A first order reaction is 38.5% complete in 480 s

(a) Calculate the rate constant.

Use ln ([At]/[A0]) = - k t

k = 1.01 x 10-3 s-1
however l would like to know how you would work it out yourself because on the calculator l get the wrong answer but when l do it on paper l get the right answer
At = 61.5
A0 = 100

ln(At/Ao) = -0.486

t = 480s

-k = -0.486/480 = 1.013 x 10-3
0
Thread starter 4 weeks ago
#3
(Original post by charco)
At = 61.5
A0 = 100

ln(At/Ao) = -0.486

t = 480s

-k = -0.486/480 = 1.013 x 10-3
I need a new calculator LOL. However, do you know how to calculate half life

t½ = ln2/k

so In 2 is the number multiplied by 2/ rate constant?
0
3 weeks ago
#4
(Original post by channnnnn)
I need a new calculator LOL. However, do you know how to calculate half life

t½ = ln2/k

so In 2 is the number multiplied by 2/ rate constant?
ln 2 is the natural logarithm of the number 2
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