I got NaOH 7%, its density is 1,08g/ml.

Calculate the molar concentration

7% means 7g NaOH in 100 g soln.

7g = how many mols? mols = g/molar mass

What is the volume? Calculate that from density. mass = volume x density.
Then M = mols/L

so then you say i need to do this,

volume=mass/destiny ---> 7(g)/1,08(g/ml)=7(ml)-->0,007(L)
and mols are ---> 7(g)/40(g/mols)=0,175(mol)

and then
0,175(mol)/0,007(L)=25(mols/L)?

Not quite.

You want mols/L for molarity. mols NaOH = 7g/molar mass NaOH = ?
Then the 100 g soln is the part that needs to be converted to L.
volume = mass/density = 100g/1.08 = 92.6 mL which is 0.0926 L.
Then M = mols NaOH/L soln.

To calculate the molar concentration of a solution, you need to know the mass of the solute and the volume of the solution.

In this case, the solute is NaOH (sodium hydroxide) and the solution has a density of 1.08 g/mL. However, we need to convert the density to grams per liter (g/L) to use it in the calculation.

To convert the density from grams per milliliter (g/mL) to grams per liter (g/L), we can use the following conversion factor:

1 g/mL = 1000 g/L

So the density of our solution is 1.08 g/mL × (1000 g/L / 1 g/mL) = 1080 g/L.

Now that we have the density in g/L, we can proceed with the calculation.

The molar concentration (M) is defined as the number of moles of solute (NaOH) divided by the volume of the solution (in liters).

To calculate the molar concentration, you need to know the molar mass of NaOH, which is determined by adding the atomic masses of sodium (Na), oxygen (O), and hydrogen (H) together. The atomic masses of Na, O, and H are approximately 22.99 g/mol, 16.00 g/mol, and 1.01 g/mol, respectively.

So the molar mass of NaOH is 22.99 g/mol + 16.00 g/mol + 1.01 g/mol = 39.00 g/mol.

Let's say you have a certain volume of the 7% NaOH solution. If you know the volume in milliliters (mL), you need to convert it to liters (L) by dividing it by 1000.

Once you have the volume of the solution in liters, you can use the following formula to calculate the molar concentration:

Molar concentration (M) = (mass of NaOH in grams / molar mass of NaOH in grams per mole) / volume of solution in liters

In this case, the mass of NaOH will be 7% of the total volume of the solution, since it is a 7% NaOH solution. Percent concentration is typically expressed as grams of solute per 100 mL of solution.

So if you have a certain volume (V) of the 7% NaOH solution, the mass of NaOH can be calculated as follows:

Mass of NaOH = 7 g/100 mL × V mL

Remember to convert the volume from mL to L by dividing it by 1000.

Now you can substitute the values into the formula to calculate the molar concentration of the NaOH solution.