Molarity (M)- is the molar concentration that a systems measured in mole of solute per liter of solution.

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The molarity definition is based upon the volume that the solution, not the volume the water.

Vocab. Lesson

Incorrect= The solution is 5.0 Molarity.

Correct= The equipment is 5.0 Molar.

Example Problems

Level 1- provided moles and also liters

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

3.0 mol | = X = 1.5M solution |

2.0 liters |

Level 2- given Molarity and also liters that solution

Determine the number of moles the salt dissolved in 5.0 liters of a 0.50M solution of salt water.

X mol | = 0.5M solution |

5.0 liters |

cross multiply, X= 2.5 mols

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

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

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first convert to moles, second 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 that moles) and also milliliters of systems (instead the liters)

Determine the molarity as soon as 55.5g that CaCl2 are dissolved to do 250.mL that solution.

1st convert to moles, 2nd convert come liters, third plug 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 that a solution of NaOH if 2 liters that the solution has 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 of NaOH in 500 milliliters of solution?

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

Jan 2002-42 What is the molarity the a solution that contains 0.50 mole of 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 just how many total moles the KNO3 should be dissolved in water to do 1.5 liters the 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 variety of moles the NaCl(s)needed to do 3.0 liters the 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 of solvent(2) moles of solute per liter the solution(3) fixed of a solution(4) volume that a solvent

Aug 2008-15 i beg your pardon phrase describes the molarity that a solution?(1) liters that solute every mole the solution(2) liters of solution per mole that solution(3) moles of solute per liter of solution(4) mole of equipment per liter the solution

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

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

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

Jan 2008-15 i beg your pardon unit deserve to be provided 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 equipment containing 20 grams of NaOH in 500 milliliters that solution?(1) 1 M (3) 0.04 M(2) 2 M (4) 0.5 M

Jan 2010-40 What is the molarity that 1.5 liters of one aqueous equipment that has 52 grams that 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