University:
Felician University
Course:
CHEM-001 | Basic Chemistry
Academic year:

2023
Views:

469

Pages:

9
Author:

MoonlitMarauder

Molarity 1 Molarity and Concentration Molarity (also sometimes referred to as concentration): which is the number of moles in one liter of solution. We calculate molarity by: Molarity (M) = ______n(moles of solute)_________ V (total volume of solution in Liters, L) Sometime “C” is used instead of M 2 Okay, but what is a mole? The Mole • The mole (mol) is a unit of measure for an amount of a chemical substance • A mole is Avogadro’s number of particles, that Is 6.02 × 1023 particles. 1 mol = Avogadro’s Number = 6.02 × 1023 units • We can use the mole relationship to convert between the number of particles and the mass of a substance The Mole The mole is just a number like: 1. Pair = 2 2. Pi (π) = 3.14159… 3. Dozen = 12 6.02x1023 MOLE is 602,000,000,000,000,000,000,000 Example: A mole of apples is 6.02x1023 apples Molarity and Concentration When calculating Molarity: •Convert solute to moles •Volume must be in liters 6 Practice Problem 1: • When Ms. Funk makes coffee, she brews (makes) 5.0 moles of ground coffee in 1.0 liter of hot water. What is the molarity of her coffee? Molarity (M) = ______n(moles of solute)_________ V (total volume of solution in Liters, L) Molarity (M) = ______5.0 moles________ 1.0 L Molarity = 5.0 mol/L Practice Problem 2: • In a beaker, Mr. Hudson mixed 5.50 moles of HCl(aq) in 700 mL of water. What is the molarity of the hydrochloric acid solution? Molarity (M) = ______n(moles of solute)_________ V (total volume of solution in Liters, L) Molarity (M) = ______5.50 moles________ 700 mL x (1L÷1000mL) Molarity = 7.9 M hydrochloric acid solution Practice Problem 3: • Sherman Jen is coming to our chemistry class to do a lab demonstration. He needs to make a 8.00 M NaCl solution and has 3.00 moles of NaCl. How much water will he need to make the solution? Molarity (M) = ______n(moles of solute)_________ V (total volume of solution in Liters, L) 8.0M = ______3.00 moles________ V V = ______3.00 moles________ 8.00 M V= 0.375 liters