Student mixed 25.0 ml of 0.100 m glucose, 15.0 ml of 0.500 m nacl and 450. ml water. what are concentrations in his solution? 5.10 mm glucose, 15.3 mm nacl 5.56 mm glucose, 16.7 mm nacl 0.556 m glucose, 0.167 m nacl 0.222 m glucose, 1.11 m nacl 0.556 m glucose, 0.0667m nac

When you start to make this operations, you will find out that the correct answer is, NaCl 5.56 mM glucose, 16.7 mM.

Explanation:

First of all you should need to find, how many mols are in the first solutions you add: In glucose you have 0.100m, so as you know they are in 1000ml,  how many, in 25 ml? this is 2,5 *10^-3 moles. In NaCl, you should do the same, 1000 ml has 0.5 mols, so how many are, in 15ml?. The answer is 7.5 *10^-3. Now, that you have your mols you have to take account the water which is in 450 ml. So, let's go again, in 450ml you have 2,5 *10^-3 moles of glucose and 7.5 *10^-3 moles of NaCl, how many moles of them, are in 1000 ml. You will get that concentrations are 0,0167 M in NaCl and 5,56 *10^-3 M. Let's see that this numbers are in M, so if u want to get mM, just *1000.