12g of water saturated by 15g of potassium chloride at 20°c calculate the solubility of potassium chloride at 20°C (K=34,CL=35.5)
What units do you want. Sometimes the unit is grams solute/100 g solvent so this would be 15 g KCl/12 g water or
15 g KCl x (100/15) = ? g KCl/100 g solvent
oops. typo. That's
15 g KCl x (100/12) = ? g KCl/100 g solvent
I need it in grams
To calculate the solubility of potassium chloride at 20°C, we first need to determine the amount of potassium chloride that has dissolved in the 12g of water.
The solubility of potassium chloride is defined as the maximum amount of solute (potassium chloride) that can dissolve in a given amount of solvent (water) at a specific temperature. In this case, we have 12g of water at 20°C.
We also know the molar masses of potassium (K) and chlorine (Cl). Potassium has a molar mass of 39 g/mol, and chlorine has a molar mass of 35.5 g/mol.
Now, let's calculate the amount of potassium chloride dissolved in the water at 20°C.
1. Convert the given mass of water into moles:
Number of moles of water = mass of water / molar mass of water
Number of moles of water = 12g / 18g/mol (molar mass of water)
Number of moles of water ≈ 0.67 moles (rounded to two decimal places)
2. Determine the molar ratio of potassium chloride to water:
From the chemical formula KCl, we can see that it contains 1 potassium (K) atom and 1 chlorine (Cl) atom per molecule.
Therefore, the molar ratio of KCl to water is 1:1.
3. Calculate the amount of potassium chloride dissolved in water:
Number of moles of potassium chloride ≈ Number of moles of water
Number of moles of potassium chloride ≈ 0.67 moles (rounded to two decimal places)
4. Convert the number of moles of potassium chloride to grams:
Mass of potassium chloride = Number of moles of potassium chloride * molar mass of potassium chloride
Mass of potassium chloride = 0.67 moles * (39 g/mol + 35.5 g/mol) (molar mass of KCl)
Mass of potassium chloride ≈ 51.45g (rounded to two decimal places)
So, the solubility of potassium chloride at 20°C is approximately 51.45 grams per 12 grams of water.