what is the molarity of a solution made by dissolving 7.5 g of magnesium nitrate in enough water to make 25.o mL of solution
Convert g to moles. moles = grams/molar mass.
Then M = moles/L
To find the molarity of a solution, we need to use the formula:
Molarity (M) = moles of solute / volume of solution (in liters)
First, we need to calculate the moles of solute (magnesium nitrate) present in the solution. The molar mass of magnesium nitrate (Mg(NO₃)₂) can be found in the periodic table:
Mg (24.31 g/mol) + 2NO₃ (2 * 14.01g/mol + 3 * 16.00 g/mol)
= 24.31 + 2 * (14.01 + 3 * 16.00) g/mol
= 148.31 g/mol
Next, we calculate the moles of magnesium nitrate (Mg(NO₃)₂) using the given mass:
moles = mass / molar mass
moles = 7.5 g / 148.31 g/mol
Now we convert the given volume from milliliters to liters:
volume = 25 mL = 25/1000 L = 0.025 L
Finally, we can substitute these values into the molarity formula to find the molarity of the solution:
Molarity = moles of solute / volume of solution
Molarity = (7.5 g / 148.31 g/mol) / 0.025 L
Please note that the final answer may be rounded depending on the level of accuracy required.