A potassium nitrate solution is prepared by dissolving 2.3 g of KNO3 in 25 mL of water. What is the concentration of this solution in units of grams of solute per 100 mL of solvent?
To find the concentration of the potassium nitrate (KNO3) solution, we need to calculate the amount of solute (KNO3) dissolved per unit volume of the solvent (water). In this case, we want to express the concentration in units of grams of solute per 100 mL of solvent.
First, we need to convert the volume of water from milliliters (mL) to liters (L) since the standard unit of concentration is typically expressed as grams per liter (g/L).
Given that there are 1000 mL in 1 L, we can convert the volume of water as follows:
25 mL รท 1000 mL/L = 0.025 L
Next, we calculate the concentration using the formula:
Concentration = (mass of solute / volume of solvent)
Given that we dissolved 2.3 g of KNO3 in 0.025 L of water, we can plug these values into the formula:
Concentration = (2.3 g / 0.025 L)
Now, we need to convert this concentration to units of grams of solute per 100 mL of solvent. Since 100 mL is equivalent to 0.1 L, we divide the concentration by 0.1:
Concentration = (2.3 g / 0.025 L) / 0.1
Now, we can solve this expression:
Concentration = 2.3 g / (0.025 L * 0.1)
Concentration = 2.3 g / 0.0025 L
Finally, we can calculate the concentration:
Concentration = 920 g/L
Therefore, the concentration of the potassium nitrate solution is 920 grams of solute per liter of solvent or 9.2 grams of solute per 100 mL of solvent.