Calculate the molarity of each.
a. 1.50 mole of NaCl in 8.00 L of solution
0.188 M NaCl
b. 270 mg of NaCl in 3.00 mL of solution
90 M NaCl
I agee with a but not b.
b)
270 mg = 0.270g
mols = 0.270/58.44 = about 0.005
M = moles/L = about 0.005/0.003 = ?
To calculate the molarity of a solution, you need to divide the number of moles of solute by the volume of the solution in liters.
a. For the first case, you have 1.50 moles of NaCl in 8.00 L of solution. To calculate the molarity, divide the number of moles by the volume in liters:
Molarity = moles/volume
Molarity = 1.50 mol/8.00 L
Molarity = 0.188 M NaCl
So, the molarity of the solution is 0.188 M NaCl.
b. For the second case, you have 270 mg of NaCl in 3.00 mL of solution. However, the volume needs to be converted to liters before calculating the molarity. Since 1 mL is equal to 0.001 L, the volume is:
Volume = 3.00 mL × 0.001 L/mL
Volume = 0.003 L
Now, you can calculate the molarity by dividing the number of moles by the volume in liters:
Molarity = moles/volume
First, you need to convert the mass of NaCl to moles. The molar mass of NaCl is 58.44 g/mol. To convert mg to g, divide by 1000:
Moles of NaCl = 270 mg × (1 g/1000 mg) × (1 mol/58.44 g)
Moles of NaCl = 0.00463 mol
Now, calculate the molarity:
Molarity = 0.00463 mol/0.003 L
Molarity = 1.54 M NaCl
So, the molarity of the solution is 1.54 M NaCl.