In the table below identify the solute and solvent in each case of the
solutions:
1.
Solutions Solvent Solute
10.0g of
KCl in 100.0g of
water
100.0g of water 10.0g of KCl
30.0 mL
of ethyl alcohol in
40.0 mL
of methyl alcohol
40.0 mL of methyl
alcohol
30.0 mL of ethyl
alcohol
4*2=8
Indicate the solubility of each of the substances below in the two solvents
like water and benzene:
2.
Substance Wate
r (polar
)
Benzene (nonpoloar)
CaCO3
(ionic solid)
Insol
uble
Insoluble
Petroleum
Jelly (nonpolar
solid)
Insol
uble
Soluble
4*2=8
What is percent by mass %(w/w), concentration of NaCl in a solution
prepared by dissolving 14.8g of NaCl of 122g of water?
3.
14.8g NaCl x 100 = 10.8%(m/m)
14.8g NaCl + 122g H2O
A solution with a volume of 425 ml is prepared by dissolving 2.64 moles of
CaCl2 in water. What is the molarity?
4.
Quiz - Chapter 8 - Solutions Quiz
CHEM 1151 - Organic & Biological Chemistry.one (On 1-6-2008).one (On 6-5-2008) Page 1
425 x 1L = 0.425L 103mL
M = 2.64 moles CaCl2 = 6.21M
0.425L
If 7.21g of KCl is dissolved in enough water to prepare 0.333L of solution,
what is the molarity?
5.
7.21g x 1.00 mole = 9.66 x 10-2 moles
74.6g
How many milliliters of water would have to be added to 250.0mL of 2.33M
solution to prepare a 0.551M solution?
6.
Cs x Vs = Cd x Vd Vd = 2.33M x 250.0mL = 1057mL
Cs = 2.33M 0.551M
Vs = 250.0mL
Cd = 0.551M Vd - Vs
Vd = ? 1057mL - 250mL = 807mL of water will be added
Complete the following table on osmolarity: 7.
Molarit
y of Solutio
n
Osmolarity
2M
CaBr2
+ 1M
KBr
CaBr2 -> Ca2 + Br
Osmolarity = 2x3=6
KBr -> K + Br
Osmolarity = 1x2=2
Total: 6+2=8
2m
KCl +
KCl -> K + Cl
Osmolarity = 2x2=4
CHEM 1151 - Organic & Biological Chemistry.one (On 1-6-2008).one (On 6-5-2008) Page 2
KCl + 1M
glucos
e
Osmolarity = 2x2=4
glucoseOsmolarity = 1x1=1
Total: 4+1=5
Indicate which way water will flow across the cell membrane of red blood
cells under each of these conditions:
8.
Condition Water
Flows Into
Cell
Water
Flows Out of
Cell
Cell immersed in concentrated
NaCl solution
X
Cells immersed in physiological
saline solution 0.9%(m/v)
There
is no flow
in or
out
There
is no flow
in or
out
Solution surrounds cell is
hypotonic
X
Indicate whether each of the changes in conditions would affect the solubility
or rate of solution of a given substance
9.
Change of Condition Solubi
lity in Water
Rate of
Solution Formatio
n
Adding more of a solid There
is no effect
Increase
s
CHEM 1151 - Organic & Biological Chemistry.one (On 1-6-2008).one (On 6-5-2008) Page 3
effect
Agitating the solid/solvent
mixture
There
is no effect
Increase
s
What is the percent by volume of isopropyl alcohol in an aqueous solution
made by diluting 75mL of pure acetone with water to give a volume of 785mL of solution?
10.
75mL x 100 = 9.6% (v/v)
785mL
How many grams of Na2S2O3 are needed to prepare 40.0mL of 5.00%(m/v)
Na2S2O3 solution?
11.
50.0mL x 5.00g Na2S2O3 = 2.50g Na2S2O3
100mL
Determine the final concentration of the 20.0mL 5.0 M NaCl solution if 30mL
of water has been added to the solution.
12.
5.0M x 20.0mL = 2.0M
50.0mL
CHEM 1151 - Organic & Biological Chemistry.one (On 1-6-2008).one (On 6-5-2008) Page 4