Molarity (M)- is the molar concentration the a equipment measured in mole of solute every liter of solution.

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The molarity definition is based upon the volume the the solution, no the volume the water.

Vocab. Lesson

Incorrect= The equipment is 5.0 Molarity.

Correct= The solution is 5.0 Molar.

Example Problems

Level 1- offered moles and also liters

Determine the molarity as soon as 3.0 mole of sucrose are dissolved to make 2.0 liters the solution.

3.0 mol= X = 1.5M solution
2.0 liters

Level 2- offered Molarity and also liters of solution

Determine the variety of moles of salt liquified in 5.0 liters of a 0.50M equipment of salt water.

X mol= 0.5M solution
5.0 liters

cross multiply, X= 2.5 mols

Level 3- given grams (instead of moles) and liters of solution

Determine the molarity when 117g of NaCl are liquified to do 0.500 liters of solution.

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1st convert come moles, 2nd plug right into the molarity equation

117g NaCl( 1mol/58.5g)= 2.00mol NaCl

2.00 mol= 4.00M solution
0.500 liters

Level 4-Given grams (instead the moles) and milliliters of solution (instead the liters)

Determine the molarity when 55.5g that CaCl2 are liquified to do 250.mL that solution.

1st convert to moles, second convert to liters, third plug right into the molarity equation

55.5g CaCl2( 1mol/111g)= 0.500mol CaCl2

250.ml( 1L/1000mL) =0.250L

0.500 mol= 2.00M solution
0.250 liters

Past Regents Questions-Follow link to examine the answers

Jan 2003-44 What is the molarity of a solution of NaOH if 2 liters of the solution includes 4 mole of NaOH?

(1) 0.5 M (3) 8 M(2) 2 M (4) 80 M

Jan. 04-41 What is the molarity of a systems containing 20 grams that NaOH in 500 milliliters that solution?

(1) 1 M (2) 2 M (3) 0.04 M (4) 0.5 M


Jan 2002-42 What is the molarity of a systems that includes 0.50 mole that NaOH in 0.50 liter the solution?(1) 1.0 M (3) 0.25 M(2) 2.0 M (4) 0.50 M


Aug. 2006-42 exactly how many full moles the KNO3 need to be liquified in water to do 1.5 liters that a 2.0 M solution?

(1) 0.50 mol (2) 2.0 mol (3) 3.0 mol (4) 1.3 mol

Aug 2005-41 What is the total number of moles that NaCl(s)needed to do 3.0 liters that a 2.0 M NaCl solution?(1) 1.0 mol (3) 6.0 mol(2) 0.70 mol (4) 8.0 mol

June 2006-16 Molarity is characterized as the(1) mole of solute per kilogram the solvent(2) moles of solute per liter the solution(3) mass of a solution(4) volume of a solvent

Aug 2008-15 which phrase explains the molarity of a solution?(1) liters the solute every mole that solution(2) liters of solution per mole that solution(3) moles of solute every liter that solution(4) mole of systems per liter the solution

June 2009-46 which sample of HCl(aq)contains the greatest number of moles that solute particles?(1) 1.0 together of 2.0 M HCl(aq)(2) 2.0 l of 2.0 M HCl(aq)(3) 3.0 l of 0.50 M HCl(aq)(4) 4.0 together of 0.50 M HCl(aq)

June 2007-13 A 3.0 M HCl(aq)solution includes a complete of(1) 3.0 grams that HCl every liter the water(2) 3.0 grams the HCl per mole the solution(3) 3.0 moles of HCl every liter the solution(4) 3.0 mole of HCl every mole of water

June 2010-14 The molarity of an aqueous systems of NaCl is defined as the(1) grams of NaCl per liter that water(2) grams of NaCl per liter the solution(3) moles of NaCl every liter that water(4) moles of NaCl per liter the solution

Jan 2008-15 which unit have the right to be supplied to express equipment concentration?(1) J/mol (3) mol/L(2) L/mol (4) mol/s

Jan 04-41 What is the Molarity the a systems containing 20 grams the NaOH in 500 milliliters of solution?(1) 1 M (3) 0.04 M(2) 2 M (4) 0.5 M

Jan 2010-40 What is the molarity the 1.5 liters of one aqueous systems that has 52 grams the lithium fluoride, LiF, (gram-formula massive =26 grams/mole)?(1) 1.3 M (3) 3.0 M(2) 2.0 M (4) 0.75 M