Ch 15 Review Sheet Questions 1-7

1. What is a solution?

homogeneous mixture

2. How does an ionic solid with strong bonds, like KBr, dissolve in water?

The negative end of a water molecule is attracted to the K+ ion, while the positive end of the water molecule is attracted to the Br^─ ion. This breaks the strong attraction and the ions are separated and dispersed throughout the solution.

3. How does a molecular solid like sugar dissolve in water?

Water molecules make H-bonds with polar O-H groups on sugar molecules, the water molecules pull the sugar molecules away from the crystal and disperse throughout the solution.

4. Distinguish between saturated, unsaturated, and supersaturated solutions.

saturated – holds maximum solute per liter of solution at that temperature.

unsaturated – holds less solute than possible at specific temperature.

supersaturated; heated, cooled will hold more than the maxiumum amount of solute for that temperature.

5. What is meant by a molar solution?

The number of moles of solute per liter of solution.

6.  Write the formula for finding the mass percent of solution.

            mass of solute/mass of solution x 100% = mass percent

7.  If 12.5 g of glucose (C₆H₁₂O₆) is dissolved in 225 g of water, what is the mass percent of glucose in the solution?  Show your work.

____12.5 g____   x 100% = 5.26%

                                    (12.5 g + 225 g)