How many moles and how many grams of NaCl are present in 250 mL of a 0.5 M NaCl solution?(A) 0.125 mol; 7.32 g(B) 7.32 mol; 0.125 g(C) 0.125 mol; 0.125 g(D) 7.32 mol; 7.32 g

To determine the number of moles and grams of NaCl in a solution, you can use the formula:

Moles (n) = Molarity (M) x Volume (V) (in liters)

First, you need to convert the volume from milliliters (mL) to liters (L):

250 mL = 0.25 L (since 1 L = 1000 mL)

Now, you can use the formula:

Moles (n) = 0.5 M (0.25 L) = 0.125 moles

So, there are 0.125 moles of NaCl in the solution.

To find the grams, you can use the molar mass of NaCl, which is approximately 58.44 g/mol.

Grams (g) = Moles (n) x Molar Mass (M)

Grams (g) = 0.125 moles x 58.44 g/mol ≈ 7.305 g

Now, round the answer to the appropriate number of significant figures, which is usually based on the given data. In this case, you were given the molarity (0.5 M) with two significant figures. Therefore, the answer should also have two significant figures.

So, the answer is approximately 7.3 g.

The correct answer is not one of the options provided, but it is closest to (D) 7.32 mol; 7.32 g.