Ch.4 - Chemical Quantities & Aqueous ReactionsWorksheetSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds
Sections
Solutions
Molarity
Osmolarity
Dilutions
Solubility Rules
Electrolytes
Molecular Equations
Gas Evolution Equations
Solution Stoichiometry
Complete Ionic Equations
Calculate Oxidation Numbers
Redox Reactions
Balancing Redox Reactions: Acidic Solutions
Balancing Redox Reactions: Basic Solutions
Activity Series
Additional Practice
Types of Chemical Reactions
Normality & Equivalent Weight
Additional Guides
Oxidation Reduction (Redox) Reactions
Oxidation Number
Net Ionic Equation
LearnAdditional Practice
Next SectionDilutions

Osmolarity (ionic molarity) represents the number of moles of ions per liter of solution. 

Osmolarity

Concept #1: Method 1: Direct Calculation of Osmolarity

Example #1: Calculate the molarity of chloride ions when dissolving 58.1 g AlCl3 in enough water to make 500 mL of solution.

Concept #2: Method 2: Osmolarity from Molarity

Example #2: What is the concentration of hydroxide ions in a 0.350 M solution of gallium hydroxide, Ga(OH)3?

Example #3: How many moles of Ca2+ ions are in 0.120 L of 0.450 M Ca3(PO4)2 solution?

Practice: Which of the following solutions will have the highest concentration of bromide ions?

Practice: How many milligrams of nitride ions are required to prepare 820 mL of 0.330 M Ba3N2 solution?

Practice: How many bromide ions are present in 65.5 mL of 0.210 M GaBr3 solution?


Previous SectionMolarity
Next SectionDilutions
Additional Problems
Which one of the following solutions will have the greatest concentration of hydroxide ions? a) 0.100 M hydrochloric acid b) 0.100 M magnesium hydroxide c) 0.100 M ammonia d) 0.300 M rubidium hydroxide e) 0.250 M calcium hydroxide
How many moles of PO43– ions are in 2.00 L of a 0.600 M solution of a Ca 3(PO4)2? a) 0.600 b) 1.000 c) 1.200 d) 2.400 e) 3.600
How many chloride ions are present in 65.5 mL of 0.210 M AlCl3 solution? a. 4.02 x 1023 chloride ions b. 5.79 x 1024 chloride ions c. 2.49 x 1022 chloride ions d. 8.28 x 1021 chloride ions e. 1.21 x 1022 chloride ions
When 5.0 grams of Na2O (MM = 61.98 g/mol) are dissolved in 1.00 L of water, what is the concentration of the Na + ions? A. 0.040 M B. 0.080 M C. 0.16 M D. 6.2 M E. 12 M
A 4.691 g sample of MgCl2 is dissolved in enough water to give 750 mL of solution.  What is the magnesium ion concentration in this solution? A)  3.70 x 10–2 M              B)  1.05 x 10–2 M              C)  6.57 x 10–2 M               D)  4.93 x 10–2 M              E)  0.131 M
How many moles of Ca2+ ions are in 0.100 L of a 0.450 M solution of Ca3(PO4)2? 
Which of the following solutions will have the highest concentration of bromide ions? a) 0.10 M NaBr b) 0.10 M CaBr2 c) 0.10 M AlBr3 d) 0.05 M MnBr4 e) All of these solutions have the same concentration of bromide ions.
Calculate the molarity of bromide ions in a solution if you mixed 12.86 g calcium bromide, CaBr2, in enough water to make 305.0 mL of solution
When 5.0 grams of Na 2O (MM = 61.98 g/mol) are dissolved in 1.00 L of water, what is the concentration of the Na+ ions? A.  0.040 M     B.  0.080 M     C.  0.16 M     D.  6.2 M     E.  12 M
What is the concentration of nitrate ions in a solution that contains 74.5 g lead (IV) nitrate, Pb(NO3)4, dissolved in 450 mL solution? ( MW of Pb(NO3)4 is 455.24 g/mol).    
How many moles of sodium ions are in 35.0 ml of a 0.750 M NaCl(aq) solution? A. 0.0263 moles B. 0.750 moles C. 0.0523 moles D. 0.375 moles E. 0.131 moles
Which of the following solutions has the largest concentration of solvated protons: (a) 0.2 M LiOH, (b) 0.2 M HI, (c) 1.0 M methyl alcohol (CH3OH)? Explain
Which of the following solutions is the most basic? (a) 0.6 M NH 3, (b) 0.150 M KOH, (c) 0.100 M Ba(OH)2.  Explain.
In each of the following pairs, indicate which has the higher concentration of Cl– ion: (b) 100 mL of 0.10 M KCI solution or 400 mL of 0.080 M LiCI solution
In each of the following pairs, indicate which has the higher concentration of Cl – ion: (c) 0.050 M HCl solution or 0.020 M CdCl2 solution.
Indicate the concentration of each ion or molecule present in the following solutions: (a) 0.25 M NaNO3Assume that the volumes are additive.
Indicate the concentration of each ion or molecule present in the following solutions: (b) 1.3 x 10–2 MgSO4Assume that the volumes are additive.
Indicate the concentration of each ion or molecule present in the following solutions: (c) 0.0150 M C6H12O6Assume that the volumes are additive.
Indicate the concentration of each ion or molecule present in the following solutions: (d) a mixture of 45.0 mL of 0.272 M NaCl and 65.0 mL of 0.0247 M (NH4)2CO3. Assume that the volumes are additive.
Indicate the concentration of each ion present in the solution formed by mixing (b) 44.0 mL of 0.100 M and Na2SO4 and 25.0 mL of 0.150 M KCl. Assume that the volumes are additive.
Indicate the concentration of each ion present in the solution formed by mixing (c) 3.60 g KCl in 75.0 mL of 0.250 M CaCl2 solution. Assume that the volumes are additive.
Calculate the sodium ion concentration when 70.0 mL of 3.0 M sodium carbonate is added to 30.0 mL of 1.0 M sodium bicarbonate.
Calculate the concentration of all ions present when 0.160 g of MgCl 2 is dissolved in 100.0 mL of solution.
What is the concentration of nitrate ions in a 0.125 M Mg(NO 3)2 solution? A) 0.375 M B) 0.0625 M C) 0.125 M D) 0.160 M E) 0.250 M
What is the total concentration of ions in a 1.1 M solution of ammonium sulfate? A. 1.1 M B. 2.2 M C. 3.3 M D. 4.4 M E. 18.7 M
A solution has 25.65 g of calcium perchlorate (MW = 238.98 g/mol) in 1.23 L. What is the concentration of perchlorate ions in M? Enter your answer with 3 decimal places and no units.
What is the molarity of Cl− in each solution?A) 0.170 M NaCl.  B) 0.150 M SrCl2.
What is the concentration (M) of lithium ions in 4.57 L of a 2.35 M Li  3P solution?a. 45.0 Mb. 14.1 Mc. 2.35 Md. 7.05 Me. 99.0 M 
What is the total molar concentration of ions in each of the following solutions, assuming complete dissociation? A 0.685 M solution of K2CO3 
What is the concentration of K+ ions in a 0.045 M K 2CO3 solution assuming complete dissociation?
K2SO4 is a strong electrolyte. Determine the concentration of each of the individual ions in a 0.650 M K 2SO4 solution. [K+] =                    M[SO42-] =                       M
The dissolution reaction is KMnO4 (s) → K+ (aq) + MnO4- (aq) If a solution is made that is 0.15 M in KMnO4, what are the concentrations of the two ions? 
1) What is the concentration of K + in 0.15 M of K 2S?  2) If CaCl2 is dissolved in water, what can be said about the concentration of the Ca 2+ ion?a. It has the same concentration as the Cl − ion.b. Its concentration is half that of the Cl − ion.c. Its concentration is twice that of the Cl − ion.d. Its concentration is one-third that of the Cl − ion.
In the laboratory you dissolve 17.7 g of sodium acetate in a volumetric flask and add water to a total volume of 125 ml. What is the molarity of the solution? What is the concentration of the sodium cation? What is the concentration of the acetate anion?
What is the concentration of nitrate ions in a 0.125 M Mg(NO  3)2 solution?a. 0.0625 Mb. 0.160 Mc. 0.250 Md. 0.125 Me. 0.375 M