Read the passage carefully and answer the Questions.
A homogeneous mixture of two or more than two components has uniform composition and properties. The binary solutions have two components, which may be solid, liquid or gas. The resultant solution has a larger amount of solvent and a smaller amount of solute. The amount of solute in a given amount of solvent decides the concentration of the resulting solution. The concentration can be expressed in various ways, like molarity, molality, normality and mole fraction.
Molarity of a solution containing 8 grams NaOH in one liter of water is
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 0.20 mol/L
Molarity = number of moles of solute / volume of solution in liters
Step 1: Find molar mass of NaOH
Na = 23, O = 16, H = 1
Molar mass = 23 + 16 + 1 = 40 g/mol
Step 2: Find number of moles of NaOH
Moles = given mass / molar mass
Moles = 8 g / 40 g/mol = 0.20 mol
Step 3: Volume of solution 1 liter
Step 4: Calculate molarity
Molarity = 0.20 mol/1 L = 0.20 mol/L
Therefore, the correct option is 0.20 mol/L.