Question

question 2
given a stock solution of 10% dextrose, how would you make 5 ml of a 0.9% dextrose solution?
a. volume of stock= ______ml
b. volume of water= ______ml
o a. 4.55 ml of stock... b. 0.45 ml of water
o a. 0.45 ml of stock... b. 4.55 ml of water
o a. 0.45 ml of stock... b. 9.55 ml of water
o a. 4.5 ml of stock... b. 0.5 ml of water

Explanation:

Step1: Use dilution formula

$C_1V_1 = C_2V_2$, where $C_1$ is the concentration of stock solution, $V_1$ is the volume of stock solution, $C_2$ is the concentration of final solution, and $V_2$ is the volume of final solution. Given $C_1 = 10\%=0.1$, $C_2 = 0.9\% = 0.009$, and $V_2=5$ ml. We solve for $V_1$.
$V_1=\frac{C_2V_2}{C_1}$

Step2: Calculate volume of stock solution

$V_1=\frac{0.009\times5}{0.1}=0.45$ ml

Step3: Calculate volume of water

The total volume of the final - solution is $V_2 = 5$ ml. The volume of water $V_w=V_2 - V_1$. So $V_w=5 - 0.45 = 4.55$ ml

Answer:

A. 0.45 ml of stock ... B. 4.55 ml of water