If 5 g of solid sodium hydroxide is dissolved in 100 mL of water, what is the molarity of the solution in moles of NaOH/L of solution (moles/L)?
how many moles of NaOH is in 5 grams? ans: 5/40
molarity= molesNaOH/.1
To find the molarity of the solution, you need to know the number of moles of sodium hydroxide (NaOH) and the volume of the solution in liters.
First, convert the mass of NaOH to moles. The molar mass of NaOH is 22.99 g/mol for sodium (Na), 16.00 g/mol for oxygen (O), and 1.01 g/mol for hydrogen (H).
Molar mass of NaOH = (22.99 g/mol) + (16.00 g/mol) + (1.01 g/mol) = 40.00 g/mol
Next, calculate the number of moles of NaOH using the given mass of 5 g:
Number of moles = mass / molar mass = 5 g / 40.00 g/mol
Now, determine the volume of the solution in liters. The given volume is 100 mL, so we need to convert it to liters:
Volume in liters = 100 mL / 1000 mL/L = 0.100 L
Finally, calculate the molarity (moles of solute per liter of solution) using the formula:
Molarity = number of moles / volume of solution in liters
Molarity = (5 g / 40.00 g/mol) / 0.100 L
Now, plug in the values:
Molarity = (0.125 mol) / (0.100 L)
Molarity = 1.25 mol/L or 1.25 M
Therefore, the molarity of the solution is 1.25 moles of NaOH per liter of solution (1.25 M).