A solution contains 0.254 moles of NaCI in 250. g of water. How many grams of solute are present and what is the mass percent (m/m)?
0.254 g, 0.102%
14.8 g, 0.0559%
O 14.8 g, 5.59%
• 0.00435 g, 0.00174%
To calculate the grams of solute, we can multiply the moles of NaCl by its molar mass. The molar mass of NaCl is approximately 58.44 g/mol.
Grams of solute = 0.254 mol NaCl * 58.44 g/mol ≈ 14.8 g
To calculate the mass percent (m/m), we divide the grams of solute by the total mass of the solution (solute + solvent) and multiply by 100.
Mass percent (m/m) = (14.8 g / (14.8 g + 250 g)) * 100 ≈ 5.59%
Therefore, the correct answer is 14.8 g, 5.59%.
To find the number of grams of solute present in the solution, we can use the formula:
mass of solute = moles of solute × molar mass of solute
First, let's calculate the molar mass of NaCl:
NaCl has a molar mass of 22.99 g/mol for sodium (Na) and 35.45 g/mol for chloride (Cl), so the molar mass of NaCl is:
22.99 + 35.45 = 58.44 g/mol
Now, let's calculate the mass of solute:
mass of solute = 0.254 moles × 58.44 g/mol
mass of solute ≈ 14.8 g
Next, let's calculate the mass percent (m/m):
mass percent (m/m) = (mass of solute / mass of solution) × 100
To find the mass of the solution, we need to sum the mass of solute and the mass of water:
mass of solution = mass of solute + mass of water
mass of solution = 14.8 g + 250 g
mass of solution ≈ 264.8 g
Now, let's calculate the mass percent (m/m):
mass percent (m/m) = (14.8 g / 264.8 g) × 100
mass percent (m/m) ≈ 5.59%
Therefore, the correct answer is:
14.8 g, 5.59%
To find the number of grams of solute in the solution, you need to multiply the number of moles of NaCl by its molar mass.
The molar mass of NaCl is the sum of the atomic masses of sodium (Na) and chlorine (Cl). The atomic mass of sodium is 22.99 g/mol, and the atomic mass of chlorine is 35.45 g/mol. Thus, the molar mass of NaCl is:
22.99 g/mol (sodium) + 35.45 g/mol (chlorine) = 58.44 g/mol
Now, multiply the number of moles of NaCl (0.254 moles) by its molar mass (58.44 g/mol):
0.254 moles x 58.44 g/mol = 14.85 g
Therefore, there are 14.85 grams of solute (NaCl) present in the solution.
To find the mass percent (m/m) of the solute, divide the mass of the solute by the mass of the solution (water + solute), and then multiply by 100.
The mass of the solution is given as 250 g (this includes the mass of the water and the solute). So, the mass percent (m/m) can be calculated as:
(14.85 g / 250 g) x 100 = 0.0594 x 100 = 5.94%
The correct answer is not listed in the options provided. However, the correct answer is approximately 14.85 g for the mass of the solute and approximately 5.94% for the mass percent (m/m) of the solute.