How many moles of KBr are present in 120mL of a 0.290M solution?
mols = M x L = ?
moles = grams/mol. wt.
4.141g/119mol.wt. = 0.03479832g
I'd rather do it in one step.
mol = M x L = 0.290 x 0.120 = 0.0348
To determine the number of moles of KBr present in a solution, you need to use the formula:
moles = concentration (molarity) x volume.
In this case, the given information is the concentration of the solution, which is 0.290 M (moles per liter), and the volume, which is 120 mL.
However, it is important to note that the volume needs to be in liters in order to match the concentration unit. So, we need to convert 120 mL to liters by dividing it by 1000:
Volume (in liters) = 120 mL / 1000 = 0.120 L
Now, we can use the formula to calculate the number of moles:
moles = 0.290 M x 0.120 L
By multiplying the concentration (0.290 M) by the volume (0.120 L), we get the number of moles of KBr present in the solution.
moles = 0.0348 mol
Therefore, there are 0.0348 moles of KBr present in 120 mL of a 0.290 M solution.