How many grams of Na2CO3 must be dissolved in 3.75 L of aqueous solution to yield a molar concentration of 1.75 molar?
How many moles do you want? That's mols = M x L = ?
Then mol = grams/molar mass. You know molar mass and mols, solve for grams.
To determine the number of grams of Na2CO3 needed to achieve a molar concentration of 1.75 M in a 3.75 L solution, we can use the formula:
moles = volume × concentration
First, we need to calculate the number of moles of Na2CO3 needed. Rearranging the formula, we have:
moles = volume × concentration
moles = 3.75 L × 1.75 M
moles = 6.5625 moles
Next, we need to convert the moles of Na2CO3 to grams. The molar mass of Na2CO3 is calculated as follows:
(2 × molar mass of Na) + (1 × molar mass of C) + (3 × molar mass of O)
(2 × 22.99 g/mol) + (1 × 12.01 g/mol) + (3 × 16.00 g/mol)
(45.98 g/mol) + (12.01 g/mol) + (48.00 g/mol)
105.99 g/mol
Using the molar mass of Na2CO3, we can calculate the mass in grams:
grams = moles × molar mass
grams = 6.5625 moles × 105.99 g/mol
grams ≈ 694.15 grams
So, approximately 694.15 grams of Na2CO3 must be dissolved in 3.75 L of aqueous solution to yield a molar concentration of 1.75 M.
To calculate the number of grams of Na2CO3 required to achieve a given molar concentration, we need to follow these steps:
Step 1: Determine the molar mass of Na2CO3.
Step 2: Use the given molar concentration and the formula of Na2CO3 to find the number of moles.
Step 3: Convert the moles to grams using the molar mass.
Let's go through these steps one by one:
Step 1: Determine the molar mass of Na2CO3.
The molar mass of Na2CO3 can be calculated by summing the atomic masses of its constituent elements: 2 sodium atoms (Na), 1 carbon atom (C), and 3 oxygen atoms (O).
The atomic masses can be found on the periodic table:
Na (sodium) = 22.99 g/mol
C (carbon) = 12.01 g/mol
O (oxygen) = 16.00 g/mol
Molar mass of Na2CO3 = (2 * Na) + C + (3 * O)
= (2 * 22.99) + 12.01 + (3 * 16.00)
= 45.98 + 12.01 + 48.00
= 105.99 g/mol (approximately)
So, the molar mass of Na2CO3 is approximately 105.99 g/mol.
Step 2: Use the given molar concentration and the formula of Na2CO3 to find the number of moles.
The molar concentration is given as 1.75 M, which means there are 1.75 moles of Na2CO3 per liter of solution. We are given that the volume of the solution is 3.75 L.
Number of moles = molar concentration * volume in liters
= 1.75 mol/L * 3.75 L
= 6.5625 moles
Step 3: Convert the moles to grams using the molar mass.
Now that we have the number of moles, we can convert it to grams using the molar mass of Na2CO3.
Mass (grams) = number of moles * molar mass
= 6.5625 moles * 105.99 g/mol
= 694.97 grams (approximately)
Therefore, approximately 694.97 grams of Na2CO3 must be dissolved in 3.75 L of aqueous solution to yield a molar concentration of 1.75 M.