1. Concentration of aqueous calcium nitrate is 25% w/w. if the density of the solution is 1.2 g/cm3. What is the concentration of solution in %w/v.
To find the concentration of the solution in %w/v, we need to calculate the mass of calcium nitrate dissolved in a volume of solution.
Given:
Concentration of aqueous calcium nitrate = 25% w/w
Density of the solution = 1.2 g/cm^3
Step 1: Convert the density from g/cm^3 to g/mL
Since 1 cm^3 = 1 mL, the density of the solution in g/mL remains the same as 1.2 g/cm^3.
Step 2: Determine the mass of the solution.
Given the density of the solution (1.2 g/mL), we can assume that 1 mL of solution weighs 1.2 grams.
Step 3: Calculate the mass of calcium nitrate in the solution.
Since the concentration is given as 25% w/w, it means that 25 grams of calcium nitrate are present in every 100 grams of the solution. Therefore, the mass of calcium nitrate in the solution is 25% of the total mass of the solution.
Let x be the mass of the solution. Since it is a 25% w/w solution, we can set up the following equation:
(25 grams of Ca(NO3)2 / 100 grams of solution) = (x grams of Ca(NO3)2 / mass of solution)
Simplifying the equation, we get:
(25 / 100) = (x / mass of solution)
0.25 = x / mass of solution
Step 4: Substitute the mass of the solution from Step 2 into the equation from Step 3 to solve for x (mass of calcium nitrate).
0.25 = x / 1.2 [Substituting the value of mass of solution as 1.2]
Simplifying the equation further, we find:
x = 0.25 * 1.2
x = 0.3 grams of Ca(NO3)2
Step 5: Calculate the concentration in %w/v.
To find the concentration in %w/v, we need to calculate the weight/volume ratio.
Weight/Volume ratio = (mass of calcium nitrate / volume of solution) * 100
Since we know that the mass of calcium nitrate is 0.3 grams, we need to determine the volume of the solution.
Given that the density is 1.2 g/mL, the volume of the solution is the mass of the solution divided by the density.
Volume of solution = mass of solution / density
Volume of solution = 1 / 1.2 = 0.833 mL
Now, we can calculate the concentration in %w/v:
(%w/v) = (0.3 g / 0.833 mL) * 100
(%w/v) = 36.04%
Therefore, the concentration of the calcium nitrate solution is approximately 36.04% w/v.