calculate the mass of potassium hydrogen phthalate which must be dissolved in water to make 500ml of a 0.2000M solution
How many mols do you want? That's M x L = ?
Then mols = grams/molar mass. You know mols and molar mass, solve for grams.
To calculate the mass of potassium hydrogen phthalate (KHP) required to make a 0.2000M solution in 500ml of water, you need to follow these steps:
Step 1: Understand the Problem
Potassium hydrogen phthalate (KHP) has a molar mass of 204.23 g/mol, and you want to make a solution with a molarity of 0.2000M in a volume of 500ml.
Step 2: Determine the Number of Moles
Molarity (M) is defined as moles of solute per liter of solution. You have the molarity (0.2000M) and the volume (500ml = 0.500L), so you can calculate the number of moles of KHP using the formula:
moles of KHP = Molarity × Volume
moles of KHP = 0.2000 mol/L × 0.500 L
moles of KHP = 0.1000 mol
Step 3: Calculate the Mass
To calculate the mass of KHP required, you need to use the molar mass of KHP (204.23 g/mol) and the number of moles.
mass of KHP = moles of KHP × molar mass
mass of KHP = 0.1000 mol × 204.23 g/mol
mass of KHP = 20.423 g
Therefore, you need 20.423 grams of potassium hydrogen phthalate (KHP) to make a 0.2000M solution in 500ml of water.