How many grams of potassium carbonate are needed to make 0.200 L of a 2.50M solution?
moles needed = M x L = ??
then moles = grams/molar mass
Solve for grams.
To determine the number of grams of potassium carbonate needed to make the specified solution, we need to use the formula:
Molarity (M) = moles (mol) / volume (L)
First, let's rearrange the formula to solve for the moles:
moles (mol) = Molarity (M) * volume (L)
Given that the Molarity (M) is 2.50M and the volume (L) is 0.200 L, we can substitute these values into the equation to calculate the number of moles of potassium carbonate required:
moles (mol) = 2.50 M * 0.200 L = 0.500 mol
Now, we can determine the molar mass of potassium carbonate (K2CO3). It consists of two potassium atoms (K) with a molar mass of 39.10 g/mol, one carbon atom (C) with a molar mass of 12.01 g/mol, and three oxygen atoms (O) with a molar mass of 16.00 g/mol.
The molar mass of potassium carbonate can be calculated as follows:
(2 x molar mass of potassium) + molar mass of carbon + (3 x molar mass of oxygen)
= (2 x 39.10 g/mol) + 12.01 g/mol + (3 x 16.00 g/mol)
= 78.20 g/mol + 12.01 g/mol + 48.00 g/mol
= 138.21 g/mol
Finally, we can calculate the number of grams of potassium carbonate using the formula:
grams = moles (mol) * molar mass (g/mol)
Substituting the values, we have:
grams = 0.500 mol * 138.21 g/mol = 69.11 g
Therefore, approximately 69.11 grams of potassium carbonate are required to make 0.200 L of a 2.50M solution.