What mass of Kbr is present in 25 mL of a 0.85 M solution of potassium chloride?
massingramsKCl=molmassKCl*.85*.025
To find the mass of KBr in the solution, we first need to determine the number of moles of KCl present in the solution using the following equation:
moles of solute = concentration of solution x volume of solution (in liters)
Concentration of KCl solution = 0.85 M
Volume of KCl solution = 25 mL = 25/1000 = 0.025 L
Therefore, moles of KCl = 0.85 M x 0.025 L = 0.02125 moles
Since the molar ratio between KCl and KBr is 1:1, the number of moles of KBr is also 0.02125 moles.
To determine the mass of KBr, we need to multiply the number of moles of KBr by its molar mass. The molar mass of KBr is the sum of the atomic masses of potassium (K) and bromine (Br).
Molar mass of K = 39.10 g/mol
Molar mass of Br = 79.90 g/mol
Molar mass of KBr = (39.10 g/mol) + (79.90 g/mol) = 119.00 g/mol
Mass of KBr = number of moles x molar mass
= 0.02125 moles x 119.00 g/mol
= 2.525 g (rounded to three decimal places)
Therefore, the mass of KBr present in 25 mL of the 0.85 M KCl solution is approximately 2.525 grams.
To find the mass of KBr present in the solution, we first need to determine the number of moles of KBr and then use its molar mass to calculate the mass.
Let's break down the steps:
Step 1: Calculate the number of moles of KCl in the solution.
Given that the solution has a concentration of 0.85 M potassium chloride (KCl) and a volume of 25 mL, we can use the formula:
moles = concentration x volume
moles of KCl = 0.85 M x 0.025 L (converting 25 mL to liters)
moles of KCl = 0.02125 mol
Step 2: Determine the number of moles of KBr.
Since KCl and KBr have a 1:1 molar ratio, the number of moles of KBr is the same as the number of moles of KCl.
moles of KBr = 0.02125 mol
Step 3: Calculate the mass of KBr.
The molar mass of KBr can be found on the periodic table. The molar mass of K is approximately 39.10 g/mol, and the molar mass of Br is approximately 79.90 g/mol. Therefore, the molar mass of KBr is:
molar mass of KBr = 39.10 g/mol + 79.90 g/mol = 119.00 g/mol
Now we can find the mass of KBr using the formula:
mass = moles x molar mass
mass of KBr = 0.02125 mol x 119.00 g/mol
mass of KBr = 2.53 g
So, the mass of KBr present in 25 mL of a 0.85 M solution of potassium chloride is approximately 2.53 grams.