A solution is prepared by dissolving 4g of sodium hydroxide who give 500ml of it.calculate the molarity of the solution.
molarity=mass/(molmass *volume)=4/(40*.5)=.2M
To calculate the molarity of a solution, you need to know the amount of solute (in moles) and the volume of the solution (in liters). In this case, we are given the mass of the solute (sodium hydroxide) and the volume of the solution.
First, we need to convert the mass of sodium hydroxide to moles. To do this, we need to know the molar mass of sodium hydroxide (NaOH), which is 23 g/mol for sodium (Na), 16 g/mol for oxygen (O), and 1 g/mol for hydrogen (H).
The molar mass of NaOH = (23 g/mol of Na) + (16 g/mol of O) + (1 g/mol of H) = 40 g/mol
Next, we can calculate the number of moles of sodium hydroxide:
Number of moles = Mass of sodium hydroxide / Molar mass of sodium hydroxide
= 4 g / 40 g/mol
= 0.1 mol
Now, we need to convert the volume of the solution from milliliters to liters. There are 1000 milliliters in 1 liter, so:
Volume of solution in liters = 500 ml / 1000 ml/L
= 0.5 L
Finally, we can calculate the molarity of the solution using the formula:
Molarity (M) = Number of moles / Volume of solution (in liters)
= 0.1 mol / 0.5 L
= 0.2 M
Therefore, the molarity of the sodium hydroxide solution is 0.2 M.