10% (m/m) Sodium Hydroxide solution, NaOH(aq) is used to break down wood fibre to make paper.

A) What mass of the solute is needed to make 250mL of 10% (m/m) solution?
B) What mass of solvent is needed?
C) What is the molar concentration of the solution?

A) To calculate the mass of the solute needed to make a 10% (m/m) solution, we can use the formula:

Mass of solute = % (m/m) × Volume of solution

Given:
% (m/m) = 10%
Volume of solution = 250 mL

Mass of solute = 10% × 250 mL
Mass of solute = 0.1 × 250 mL
Mass of solute = 25 g

Therefore, 25 grams of the solute is needed to make 250 mL of the 10% (m/m) solution.

B) To find the mass of the solvent needed for a given volume of solution, we subtract the mass of the solute from the total mass of the solution.

Given:
Mass of solute = 25 g
Volume of solution = 250 mL

Let's assume the density of the solution is equal to the density of water, which is approximately 1 g/mL.

Mass of solvent = Mass of solution - Mass of solute
Mass of solvent = 250 g - 25 g
Mass of solvent = 225 g

So, 225 grams of solvent is needed.

C) The molar concentration of the solution can be calculated using the formula:

Molar concentration = Moles of solute / Volume of solution (in liters)

First, we need to calculate the moles of the solute.

Given:
Mass of solute = 25 g
Molar mass of NaOH = 22.99 g/mol + 16 g/mol + 1.01 g/mol = 39.01 g/mol

Moles of solute = Mass of solute / Molar mass of solute
Moles of solute = 25 g / 39.01 g/mol
Moles of solute ≈ 0.641 mol

Next, we convert the volume of the solution to liters:

Volume of solution = 250 mL = 250 mL × 1 L / 1000 mL
Volume of solution = 0.25 L

Finally, we can calculate the molar concentration:

Molar concentration = 0.641 mol / 0.25 L
Molar concentration ≈ 2.56 mol/L or 2.56 M

Therefore, the molar concentration of the solution is approximately 2.56 mol/L or 2.56 M.

A) To determine the mass of the solute needed to make a 10% (m/m) sodium hydroxide solution, we need to know the definition of a 10% (m/m) solution. This means that for every 100 grams of the solution, 10 grams is sodium hydroxide.

Step 1: Convert the given volume of the solution to the mass of the solution.
Since we have 250 mL of solution, we need to convert this to grams. The density of water is approximately 1 g/mL, so we can assume that the mass of the solution is equal to its volume in grams. Therefore, the mass of the solution is 250 grams.

Step 2: Calculate the mass of the solute.
Since the solution is 10% (m/m) sodium hydroxide, 10% of the mass of the solution is sodium hydroxide.
10% of 250 grams = (10/100) * 250 grams = 25 grams.

Therefore, 25 grams of sodium hydroxide is needed to make 250 mL of a 10% (m/m) solution.

B) The mass of the solvent can be calculated by subtracting the mass of the solute from the mass of the solution.

Mass of solvent = Mass of solution - Mass of solute
Mass of solvent = 250 grams - 25 grams
Mass of solvent = 225 grams

Therefore, 225 grams of solvent is needed to make 250 mL of a 10% (m/m) solution.

C) To calculate the molar concentration of the solution, we need to know the molar mass of sodium hydroxide (NaOH). The molar mass of sodium is 22.99 g/mol, oxygen is 16.00 g/mol, and hydrogen is 1.01 g/mol.

The molar mass of NaOH = (22.99 g/mol) + (16.00 g/mol) + (1.01 g/mol)
= 40.00 g/mol

Next, we need to calculate the number of moles of sodium hydroxide in the given mass.

Number of moles = Mass of solute / Molar mass
Number of moles = 25 grams / 40.00 g/mol
Number of moles ≈ 0.625 mol

Finally, we need to calculate the molar concentration of the solution.

Molar concentration = Number of moles / Volume of solution (in liters)
Volume of solution = 250 mL = 0.250 L

Molar concentration = 0.625 mol / 0.250 L
Molar concentration = 2.5 mol/L

Therefore, the molar concentration of the 10% (m/m) sodium hydroxide solution is approximately 2.5 mol/L.

(g solute/250 g)*100 = 10%. Solve for g solute.

250 g solution - 25 g solute = ?? g water.

Convert g solute to moles, then M = moles/L.