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1. Obtain 10.0 mL of 0.10 M HCl. Transfer 9.0 mL to a 50 mL or 100 mL beaker lab

ID: 820643 • Letter: 1

Question

1. Obtain 10.0 mL of 0.10 M HCl. Transfer 9.0 mL to a 50 mL or 100 mL beaker labeled HCl #1. Dilute 1.0 mL of the 0.10 M HCl to 10.0 mL with deionized water in your graduated cylinder, transfer to a 50 mL or 100 mL beaker, and label HCl #2. Measure the pH of each solution.


2. Obtain 10.0 mL of 0.10 M HC2H3O2. Transfer 9.0 mL to a 50 mL or 100 mL beaker labeled HC2H3O2 #1. Dilute 1.0 mL of the 0.10 M HC2H3O2 to 10.0 mL with deionized water in your graduated cylinder, transfer to a 50 mL or 100 mL beaker, and label HC2H3O2 #2. Measure the pH of each solution.


Now, calculate the (1) molarity and (2) calculated pH for each of the following:

HCl #1 (measured pH = 1.50)

HCl #2 (measured pH = 2.50)

HC2H3O2 #1 (measured pH = 3.00)

HC2H3O2 #2 (measured pH = 3.50)

Explanation / Answer

Hcl

1. moles of hcl in 9 ml = 0.1*0.009 = 0.9milli moles

conc=[H] =0.1 M

molarity=0.1M

PH=-log[H]= -(-1)=1

2.moles of hcl = 0.1*0.001= 0.1 millimoles

con, [H]= 0.1/10 = 0.01

molarity=0.01M

PH=-log[H]=2


HC2H3O2

1. conc ,[OH]= 0.1M

molarity=0.1M

[OH][H]=10^-14 ...[H]=10^-13

PH=-log[H]=13

2.moles =0.1 millimoles

conc=[OH]=0.1/10=0.01M

molarity=0.01M

[OH]*[H]=10^-14.......[H}=10^-12

PH= 12