Question

q2. a total of 1,000 ml of a 8% nacl solution is needed. however, only a 12% solution of sodium chloride is available. how many milliliters of the 12% nacl solution are needed to make 1,000 ml of the 8% solution?

Explanation:

Step1: Define variables

Let \( x \) be the volume (in mL) of the 12% NaCl solution needed. The amount of NaCl in the 12% solution is \( 0.12x \). The final solution is 1000 mL of 8% NaCl, so the amount of NaCl in the final solution is \( 0.08 \times 1000 = 80 \) grams (or mg, the unit doesn't matter as long as consistent).

Step2: Set up equation

Since the amount of NaCl before and after dilution remains the same, we have the equation:
\( 0.12x = 80 \)

Step3: Solve for x

Divide both sides by 0.12:
\( x=\frac{80}{0.12}=\frac{8000}{12}=\frac{2000}{3}\approx666.67 \)

Answer:

\(\frac{2000}{3}\) mL (or approximately 666.67 mL)