The question is incomplete, here is the complete question:
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?
A. 5.10 mM glucose, 15.3 mM NaCl
B. 5.56 mM glucose, 16.7 mM NaCl
C. 0.556 mM glucose, 0.167 mM NaCl
D. 0.222 mM glucose, 1.11 mM NaCl
E. 0.556 mM glucose, 0.0667 mM NaCl
<u>Answer:</u> The concentration of glucose and NaCl in the solution is 5.10 mM and 15.3 mM respectively.
<u>Explanation:</u>
To calculate the number of moles for given molarity, we use the equation:
.....(1)
Molarity of glucose solution = 0.100 M
Volume of solution = 25.0 mL
Putting values in equation 1, we get:

Molarity of NaCl solution = 0.500 M
Volume of solution = 15.0 mL
Putting values in equation 1, we get:

Total volume of solution = 25.0 + 15.0 + 450. = 490. mL
Now, calculating the concentration of glucose and NaCl in the solution by using equation 1:
Using conversion factor: 1 M = 1000 mM
Moles of glucose = 0.0025 moles
Volume of solution = 490. mL
Putting values in equation 1, we get:

Moles of NaCl = 0.0075 moles
Volume of solution = 490. mL
Putting values in equation 1, we get:

Hence, the concentration of glucose and NaCl in the solution is 5.10 mM and 15.3 mM respectively.