Calculating Molarity

Formula for molarity

moles of solute/liters of solution

What is the solute?

the substance that is dissolved, the smaller component present

A "solution" is also called...

A homogeneous mixture

Sea water contains roughly 28.0 g of NaCl per liter. What is the molarity of sodium chloride in sea water?

x = 0.479 M

What is the molarity of 0.0500 mol Na2CO3 dissolved in 400.0 mL solution?

x = 0.125 M

You need 15.0mL of a .500M Na2CO3 solution, but you only find 10.0mL of a 1.25M solution. How do you make it?

Pipet 6.00mL of 1.25M Na2CO3 into a vol. flask. Add water until total vol is 15.0mL.

How many moles of Na2CO3 are there in 10.0 L of 2.0 M solution?

20. mol

How many moles of Na2CO3 are in 10.0 mL of a 2.0 M solution?

0.020 mol

How could you make 750.0 mL of 2.00 M Na2CO3 solution? (You only find the solid in the supply room.)

Weigh & place 159 g Na2CO3 in a vol. flask & add water until total volume is 750.0 mL.

What volume (in mL) of 18.0 M H2SO4 is needed to contain 2.45 g H2SO4?

1.39 mL

What volume (in mL) of 12.0 M HCl is needed to contain 3.00 moles of HCl?

250. mL

How many grams of Ca(OH)2 are needed to make 100.0 mL of 0.250 M solution?

1.85 g