How many grams of NaCl do you need to make 150ml of a 0.8M stock solution?
Molarity (M) = mol / liter
= moles/ 1000ml
Therefore, 0.8M = 0.8 mol/ 1000 ml
Know that the units cancel out to mol:
(0.8 mol/1000 ml)*(150ml) = ? mol
if you multipy ? mol by the molar mass of NaCl , you would end up with grams of NaCl
(? mol)*(__ g/ mol)= ___g NaCl
0.12
To determine the number of grams of NaCl needed to make a 0.8M stock solution with a volume of 150ml, you will need to use the molarity equation:
Molarity (M) = moles of solute / liters of solvent
In this case, the solute is NaCl, and the solvent is water. We need to find the moles of NaCl first, then convert it to grams.
Step 1: Convert the volume from ml to liters.
150ml = 150/1000 = 0.15 L
Step 2: Use the molarity equation to find the moles of NaCl.
0.8M = moles of NaCl / 0.15 L
Rearranging the equation:
moles of NaCl = 0.8M * 0.15 L
moles of NaCl = 0.12 moles
Step 3: Convert moles of NaCl to grams using the molar mass of NaCl.
The molar mass of NaCl is 58.44 g/mol.
grams of NaCl = moles of NaCl * molar mass of NaCl
grams of NaCl = 0.12 moles * 58.44 g/mol
grams of NaCl = 7.01 grams
Therefore, you need 7.01 grams of NaCl to make a 0.8M stock solution with a volume of 150ml.
To determine the number of grams of NaCl needed to make a 0.8M stock solution in 150ml, you need to follow these steps:
1. Convert the given volume (in ml) to liters: 150ml ÷ 1000 = 0.15L
2. Calculate the molar mass of NaCl (sodium chloride). The molar mass of NaCl is the sum of the atomic masses of sodium (22.99 g/mol) and chlorine (35.45 g/mol): 22.99 g/mol + 35.45 g/mol = 58.44 g/mol.
3. Use the formula for molarity (M) to find the number of moles of NaCl needed: M = moles ÷ liters. Rearrange the formula to solve for moles: moles = M × liters.
For a 0.8M solution, the moles of NaCl can be calculated as follows: moles = 0.8M × 0.15L = 0.12 moles.
4. Finally, use the number of moles of NaCl and its molar mass to determine the grams of NaCl needed: grams = moles × molar mass.
Substituting the values, you get: grams = 0.12 moles × 58.44 g/mol = 7.01 grams.
Therefore, you need approximately 7.01 grams of NaCl to make a 0.8M stock solution in 150ml.