mole fraction and molality.pdf applied chem

mole fraction and molality applied chemistry

2. MOLEFRACTION
&
MOLARITY

3. MOLEFRACTION

4. MOLE
The ratio of the number of
moles of one component of a
solution or other mixture to the
total number of moles
representing all the components.
FRACTION

5. SOLVING A
MOLE FRACTION

6. FORMULA:
??????
??????=
�
??????
�
���??????�
•??????
?????? = Mole ratio
•�
??????= Amount of moles
•�
�??????�??????�= ??????�tal amounf of mole
Remember that the sum of all mole fractions in a mixture
always equals 1.

7. SAMPLE PROBLEM:
If you have 2 moles of oxygen (�
2) and 3 moles of
nitrogen (�
2) in a gas mixture. What is the mole
fraction of oxygen and nitrogen?
Given: 2 moles of oxygen (�
�)
3 moles of nitrogen (�
�)
Formula: ??????
??????=
�??????
����??????�

8. SAMPLE PROBLEM:
Solution:
??????
�
�
=
����
����+����
=
�
�
=�.�
??????
�
�
=
����
����+����
=
�
�
=�.�
Sum of 2 mole fractions is = 1

9. SAMPLE PROBLEM 2:
A mixture contains 10 grams of hydrogen gas (H₂) and 40
grams of oxygen gas (O₂). Calculate the mole fraction of each
gas in the mixture.
Given: 10 grams (H₂)
40 grams (O₂)
Formula: ??????
??????=
�
??????
�
���??????�
mol=
�??????�� ??????� ��??????��
���??????� �??????��

10. SAMPLE PROBLEM2:
Solution:
moles H₂ =
10??????
2??????/�??????�
=5 ��� �?????? H₂
??????
H₂
=
����
����+�.�����
= 0.8
Convert:
Substitute
moles O₂ =
40??????
32??????/�??????�
=1.25 ��� �?????? O₂
??????
O₂
=
�.�����
����+�.�����
= 0.2
Sum of 2 mole fractions is = 1

11. MOLARITY

12. MOLARITY
The moles of solute per
liters of a solution or a
mixture.

13. SOLVING A
MOLARITY

14. FORMULA:
M=
����� �� ������
������ �� �����??????�� ??????� �??????����
•M= Molarity
•Moles of solute =the amount of solute (in
moles)
•V����� �� �����??????�� ??????� �??????���� = total
volume of the solution in liters.

15. SAMPLE PROBLEM:
Richard have 0.5 moles of sodium chloride
(NaCl) dissolved in 2 liters of water. What is the
molarity of the solution?
Given: 0.5 moles (NaCl)
2 liters of water
Formula:
m=
����� �� ������
������ �� �����??????�� ??????� �??????����

16. SAMPLE PROBLEM:
Solution:
M=
�.� �����
� �??????����
=�.�� ���/�
Molarity of the solution is = 0.25

17. SAMPLE PROBLEM 2:
If 5 grams of sodium hydroxide (NaOH) is
dissolved in enough water to make 500 mL of
solution, what is the molarity?
Given: 5 grams (NaOH)
500 mL of solution
Formula: m=
����� �� ������
������ �� �����??????�� ??????� �??????����

mol=
�??????�� ??????� ��??????��
���??????� �??????��

18. SAMPLE PROBLEM 2:
Solution:
moles NaOH=
5??????�??????��
40??????/�??????�
=0.125 ��� �?????? �??????�??????
m=
�.��� ���
�.� �
= 0.25 Mol/L
Convert:
500 mL ÷1000 = 0.5 L
Substitute

19. ASSIGNMENT

20. Mole fraction 3#
A solution is made by mixing
4 moles of nitrogen gas (N₂)
and 6 moles of oxygen gas
(O₂). Calculate the mole
fraction of nitrogen and
oxygen in the mixture.
Given: 2pts
Formula: 2pt
Solution: 2pts
Final Ans.:2pts

21. Molarity 4#
Given: 2pts
Formula: 1pt
Solution: 1pts
Final Ans.:1pts
You have 2 moles of potassium
chloride (KCl) dissolved in 0.5
liters of water. What is the
molarity of the KCl solution?

22. THANK YOU
TABLE 3
PAUL VINCENT BUDOK
ROJEN LIMOS
AMBREY ALARTE
KIAN RODRIGUEZ
RYNDZ BELGIRA