Question

Can someone help me solve this?

Answer 1

The M units cancel out.

Answer 2

\(\dfrac{x (0.240 ~M)}{(100.0~mL - x)(0.100 M)} = 0.63\)

Ok, I think I copied it correctly.

Answer 3

\(\dfrac{x (0.240 ~\cancel{M})}{(100.0~mL - x)(0.100 \cancel{M})} = 0.63\)

\(\dfrac{x (0.240)}{(100.0~mL - x)(0.100)} = 0.63\)

Answer 4

The first step was just to cancel out M to make it a little simpler.

Answer 5

Got ya.

Answer 6

Now, multiply both sides by the denominator.

Answer 7

\( \small\dfrac{x (0.240 ~M)}{(100.0~mL - x)(0.100 M) } \times (100.0~mL - x)(0.100 M) = 0.63 \times (100.0~mL - x)(0.100 M)\)

The idea here is to get rid of the denominator on the left side.

Answer 8

\( \small\dfrac{x (0.240 ~M)}{\cancel{(100.0~mL - x)(0.100 M) }} \times \cancel{(100.0~mL - x)(0.100 M)} = 0.63 \times (100.0~mL - x)(0.100 M)\)

Leaving:

\(x (0.240) = 0.63 \times (100.0~mL - x)(0.100)\)

Now we rewrite the left side and multiply 0.63 and 0.100 on the right side.

\(0.240x = 0.0630 (100.0~mL - x)\)

Answer 9

distribute the .63?

Answer 10

Now we distribute on the right side:

\(0.240x = 6.30~mL - 0.630x\)

Answer 11

Correct, we distribute 0.63

Answer 12

Just add the .630x and we got it?

Answer 13

Wait. I copied wrong from one line to the other.
There is a 0.063 above, and I copied it to the next line as 0.63.

Answer 14

:) its ok.

Answer 15

Go back to where I had this line.

\(0.240x = 0.0630 (100.0~mL - x)\)

Answer 16

Now we distribute the 0.063, not 0.63, on the right side.

0.240x = 6.3 mL - 0.063

Now we add 0.063 to both sides:

0.303x = 6.3 mL

Now we divide both sides by 0.303

x = 20.79 mL

Since you need 3 significant figures, the answer is

x = 20.8 mL

Answer 17

Thank you so much. I really needed this!!!!!!!

Answer 18

You're welcome.