CHEM 120 Possible Questions with Answers
1) When calculating the Molarity, the correct units are
a. grams/ml
b. grams x
ml c.
moles/L
d. moles/ml
2) To calculate the osmolarity of a 5 M solution of Na3N what is needed?
a. The molecular weight of the solute
b. The number of liters of solution
c. The number of ions that the solute makes when going into solution.
d. The weight of the Na3N used.
3) Explain how to calculate moles of a specific compound. What is needed and how
does the calculation proceed?
grams / molecular weight
4) I have 20 ml of a 10M HCl. How many ml of 2 M HCl can I make? 100ml dilution
problem
5) Given 10 grams of NaCl dissolved in water to give a total volume of 150 ml. What is
the wt./vol
%? 10gms/150 ml x 100 = 6.67% g/ml
6) Calculate the Molarity of a solution of 50 gms of NaF (MW – 41 gms/mol) in 125ml
of water. a. 50grms/41 grm/mol = 1.2 mol 125ml/1000ml = .125 L M =
1.2mol/.125L = 9.6M
7)
8) The solute is defined as
a. The material that is being dissolved in a solvent.
, b. The sum of the weight of the material dissolved and the total volume of solution.
c. The Molarity divided by the Osmolarity.
d. Whatever does not dissolve in a solvent; the remainder.
9) Name 5 different types of concentration M, Osm and 3 %s
Acid and Base
1) A conjugate base is defined as what;
a. Whatever the pH is of a
solution. b. An acid after it loses
its proton.
c. Any base that will react with the acid.
d. The products of a neutralization reaction
2) Buffers can be made from
a. Weak acid and weak base
b. Weak base and its conjugate acid
c. Strong acid and weak base
d. Strong acid but diluted to a lower molarity.
1) When calculating the Molarity, the correct units are
a. grams/ml
b. grams x
ml c.
moles/L
d. moles/ml
2) To calculate the osmolarity of a 5 M solution of Na3N what is needed?
a. The molecular weight of the solute
b. The number of liters of solution
c. The number of ions that the solute makes when going into solution.
d. The weight of the Na3N used.
3) Explain how to calculate moles of a specific compound. What is needed and how
does the calculation proceed?
grams / molecular weight
4) I have 20 ml of a 10M HCl. How many ml of 2 M HCl can I make? 100ml dilution
problem
5) Given 10 grams of NaCl dissolved in water to give a total volume of 150 ml. What is
the wt./vol
%? 10gms/150 ml x 100 = 6.67% g/ml
6) Calculate the Molarity of a solution of 50 gms of NaF (MW – 41 gms/mol) in 125ml
of water. a. 50grms/41 grm/mol = 1.2 mol 125ml/1000ml = .125 L M =
1.2mol/.125L = 9.6M
7)
8) The solute is defined as
a. The material that is being dissolved in a solvent.
, b. The sum of the weight of the material dissolved and the total volume of solution.
c. The Molarity divided by the Osmolarity.
d. Whatever does not dissolve in a solvent; the remainder.
9) Name 5 different types of concentration M, Osm and 3 %s
Acid and Base
1) A conjugate base is defined as what;
a. Whatever the pH is of a
solution. b. An acid after it loses
its proton.
c. Any base that will react with the acid.
d. The products of a neutralization reaction
2) Buffers can be made from
a. Weak acid and weak base
b. Weak base and its conjugate acid
c. Strong acid and weak base
d. Strong acid but diluted to a lower molarity.
