Question

Please help me solve this step by step?

Answer 1

average rate = final concentration - initial concentration / final time - initial time

average rate = 0.250 M - 1.000 M / 4.32 x 10^4 s - 0 s = 1.74 x 10^-5 M / s

I know the answer is 1.74 x 10^-5, but I don't know I my teacher got the answer.

Answer 2

physics

Answer 3

Yeah, I know, but I don't know how my teacher got 1.74 x 10^-5.

Answer 4

okay

Answer 5

i think 1 M should go before 0.250 M

Answer 6

otherwise it should be negative

Answer 7

Your teach is correct, the exact value is -1.7361111111... E -5 (that's ten to the -5th). You need to put your parenthesis up... I assumed the parenthesis and got this

Answer 8

The negative implies something is switched, but otherwise ok

Answer 9

write like this
(0.250 M - 1.000 M) / (4.32 x 10^4 s - 0 s )

or this:
\[\frac{0.250 M - 1.000 M}{4.32 x 10^4 s - 0 s }\]

Answer 10

Yeah, that's the right question.

Answer 11

\[0.250 M - 1.000 M / 4.32 x 10^4 s - 0 s \neq (0.250 M - 1.000 M) / (4.32 x 10^4 s - 0 s )\]

This is a common mistake I see people make this again and again, forgetting order of operations because of a lack of parenthesis :D

Answer 12

\[\frac{0.250 M - 1.000M}{4.32 \times 10^4}\]
\[\frac{250,000 - 1,000,000}{4.32 \times 10^4}\]
\[\frac{-750,000}{4.34 \times 10^4}\]
\[=-1.7361111\]

Answer 13

Thankyou both for all the help! :)