Question

how many grams of nacl would you need to prepare 550 ml of a 2.5m solution?

Answer 1

Answer on Question #41908 – Chemistry – Other

Question:

How many grams of NaCl would you need to prepare 550 ml of a 2.5M solution?

Solution:

$$C = \frac{\partial}{V}$$

where C is concentration of NaCl; V is volume of NaCl; $\partial$ is number of moles of NaCl.

$$C = 2.5 \, \text{M}$$ $$V = 550 \, \text{ml} = 0.55 \, \text{L}$$

Then

$$\partial = C \cdot V = 2.5 \cdot 0.55 = 1.375 \, \text{mole};$$ $$\partial = \frac{m}{M}$$

where m is mass of NaCl, M is molecular mass of NaCl.

$$M(\text{NaCl}) = 22.99 + 35.45 = 58.44 \, \text{g/mole}$$

Then

$$m = \frac{\partial \cdot M}{M} = 1.375 \, \text{mole} \cdot 58.44 \, \text{g/mole} = 80.355 \approx 80.4 \, \text{g}$$

Answer: 80.4 grams of NaCl.

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