I was told to make a 2/25 dilution of a solution with water. If I had 30 mL the solution....how much water should I add? I just don't understand what the ratio implys.
2007-02-08 02:12:51 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
Greetings!
A 2/25 dilution means that you have to take 2ml of the starting solution and add water TILL 25ml (23ml of water).
At the end, you would have 25ml of the dilution and 28ml of the starting solution.
If you want to make de dilution with de whole starting solution, you must use 30ml of the solution, and add water TILL 375ml (345ml of water).
Good luck!
2007-02-08 02:27:17 · answer #1 · answered by wyrond 3 · 1⤊ 0⤋
The ratios mean that you had diluted to 2/25th the strength of the orginal sample.
If you had a pipet that measured 2 ml, then you would add that to a graduated cylinder and dilute to 25 ml total volume.
If you were to use the entire 30 ml then you would make a ratio and solve for x
30/x = 2/25, x being the entire volume of the final solution.
Be carefull that they did not use the words 'parts' in the statement of the problem, that would be a different situation of adding 25 parts diluent to 2 parts of your sample.
2007-02-08 10:29:04 · answer #2 · answered by Anonymous · 0⤊ 0⤋
The dilution is 2/25. This is a simple ratio.
2/25 = 30/x. Cross multiply
750=2x
x= 375
This means you will add 375 ml of water.
2007-02-08 10:23:40 · answer #3 · answered by Shaunie81 1 · 0⤊ 0⤋
It seems to mean take "2 parts" of solution and add water to "25 parts." So if you have 30 mL, each of the "2 parts is 15 mL, and you're to dilute it up to 15 x 25 = 375 mL.
2007-02-08 10:21:40 · answer #4 · answered by steve_geo1 7 · 0⤊ 0⤋
that's 2 parts solution + 23 parts water. the second number is the number of parts. that's why a 1:2 dilution is also called a 1:1 dilution
2007-02-08 12:03:15 · answer #5 · answered by shiara_blade 6 · 0⤊ 0⤋
375 mL of water
2007-02-08 10:21:58 · answer #6 · answered by koala_beng 2 · 0⤊ 0⤋