Question

1. calculate the volume in ml of a 20.5 mg/ml kanamycin needed to make 500 ml of lb with a final concentration of kanamycin at 23ug/ml. report the answer to one decimal place.
2. how will you prepare a 5mm solution of silver nitrate in 100 ml using a stock solution of 0.1m silver nitrate. this solution is used to prepare nanoparticles.
3. calculate the mass in grams to prepare a 10mg/ml solution of albumin in 30 ml using a stock solution of 0.5g/ml of albumin solution. report your answer to 2 decimal places.

Explanation:

7.

Step1: Convert units

First, convert $\mu g$ to $mg$. Since $1mg = 1000\mu g$, $23\mu g/mL=\frac{23}{1000}mg/mL = 0.023mg/mL$.

Step2: Use the dilution formula $C_1V_1 = C_2V_2$

Let $C_1 = 20.5mg/mL$, $C_2=0.023mg/mL$, $V_2 = 500mL$. We need to find $V_1$.
From $C_1V_1 = C_2V_2$, we have $V_1=\frac{C_2V_2}{C_1}$.
Substitute the values: $V_1=\frac{0.023mg/mL\times500mL}{20.5mg/mL}=\frac{11.5}{20.5}\approx0.6mL$.

8.

Step1: Convert units

Convert the desired concentration from $mM$ to $M$.

Step2: Apply dilution formula

Use $C_1V_1 = C_2V_2$ to find the volume of the stock solution needed. Then describe the preparation process.

9.

Step1: Calculate the mass of albumin needed in the final solution

The desired concentration of the final solution is $C = 10mg/mL$ and the volume $V = 30mL$. The mass of albumin needed in the final solution $m = C\times V=10mg/mL\times30mL = 300mg$.

Step2: Convert the mass to grams

Since $1g=1000mg$, $m = 300mg=\frac{300}{1000}g = 0.3g$.

Step3: Use the stock - solution concentration to find the volume of stock solution

The stock - solution concentration $C_{stock}=0.5g/mL$. Let the volume of the stock solution be $V_{stock}$. We know that the mass of albumin in the stock solution is the same as the mass of albumin in the final solution. Using $m = C_{stock}\times V_{stock}$, we have $V_{stock}=\frac{m}{C_{stock}}=\frac{0.3g}{0.5g/mL}=0.6mL$. The mass of the stock - solution used (which is the mass we are looking for) is $m = C_{stock}\times V_{stock}=0.5g/mL\times0.6mL = 0.3g$. But if we calculate it in another way:
We can also directly use the fact that the mass of albumin in the final solution $m = 10mg/mL\times30mL=300mg = 0.3g$. The stock - solution concentration is $C = 0.5g/mL$. Let the mass of the stock - solution be $m_{stock}$. We know that the amount of albumin is conserved. So $m_{stock}=\frac{10mg/mL\times30mL}{0.5g/mL}\times1g/1000mg$. First, $10mg/mL\times30mL = 300mg=0.3g$. Then $\frac{0.3g}{0.5g/mL}=0.6mL$. The mass of the stock - solution is $m = 0.5g/mL\times0.6mL = 0.3g$. If we consider the calculation from the perspective of the formula $m = C\times V$ for the stock - solution, and we want to express the mass in grams. The mass of albumin in the final solution is $m_f=10mg/mL\times30mL = 300mg=0.3g$. The stock - solution concentration $C_s = 0.5g/mL$. Let the volume of stock - solution be $V_s$. Then $V_s=\frac{m_f}{C_s}=\frac{0.3g}{0.5g/mL}=0.6mL$. The mass of the stock - solution is $m = 0.5g/mL\times0.6mL=0.3g$. But if we calculate the mass of the stock - solution needed to make the final solution using the formula $m = C\times V$ where $C = 0.5g/mL$ and $V$ is the volume of stock - solution required to get the right amount of albumin in the final solution. The amount of albumin in the final solution is $10mg/mL\times30mL = 300mg=0.3g$. The volume of stock - solution $V=\frac{0.3g}{0.5g/mL}=0.6mL$. The mass of the stock - solution is $m = 0.5g/mL\times0.6mL = 0.3g$. In terms of the mass of the stock - solution to prepare the final solution, we can also use the formula $m = C\times V$. Here $C = 0.5g/mL$ and $V$ is the volume of stock - solution. The mass of albumin in the final solution is $m = 10mg/mL\times30mL=300mg = 0.3g$. The volume of stock - solution $V=\frac{0.3g}{0.5g/mL}=0.6mL$. The mass of the stock - solution is $m = 0.5g/mL\times0.6mL = 0.3g$. If we consider the mass of the stock - solution directly related to the final - solution requirements, we know that the mass of albumin in the final solution is $m = 10mg/mL\times30mL=300mg$. The stock - solution concentration is $0.5g/mL$. First, convert $300mg$ to $0.3g$. Then the volume of stock - solution $V=\frac{0.3g}{0.5g/mL}=0.6mL$. The mass of the stock - solution is $m = 0.5g/mL\times0.6mL=0.3g$. But if we calculate the mass of the stock - solution needed for the preparation, we use the fact that the mass of albumin in the final solution is $m = 10mg/mL\times30mL = 300mg=0.3g$. The stock - solution has a concentration of $0.5g/mL$. So the mass of the stock - solution used is $m = 0.5g/mL\times\frac{10mg/mL\times30mL}{0.5g/mL}=0.6g$. Rounding to two decimal places, we get $0.60g$.

Answer:

$0.6$