Answer:
To determine the number of grams of NaCl needed to make a 25.0 ml solution with a concentration of 5.55 M, we'll use the formula:
mass = volume * concentration * molar mass
First, let's calculate the molar mass of NaCl (sodium chloride). The molar mass of Na is approximately 22.99 g/mol, and the molar mass of Cl is approximately 35.45 g/mol. Since NaCl has a 1:1 ratio of Na to Cl, the molar mass of NaCl is:
Molar mass of NaCl = 22.99 g/mol + 35.45 g/mol = 58.44 g/mol
Now, we can calculate the mass of NaCl needed:
mass = volume * concentration * molar mass
= 25.0 ml * 5.55 mol/L * 58.44 g/mol
Before performing the calculation, we need to convert the volume from milliliters (ml) to liters (L) since the concentration is given in moles per liter (mol/L):
volume = 25.0 ml = 25.0 ml * (1 L / 1000 ml) = 0.025 L
Now, we can substitute the values and calculate the mass:
mass = 0.025 L * 5.55 mol/L * 58.44 g/mol
Performing the calculation:
mass = 0.025 L * 5.55 mol/L * 58.44 g/mol = 8.097 g
Therefore, approximately 8.097 grams of NaCl are needed to make a 25.0 ml solution with a concentration of 5.55 M.