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8. Rinse and dry the temperature probe, cup, and stirring rod. Dispose of the solution as directed.
9. Repeat steps 4-8, using 100.0mL of 0.5M hydrochloric acid instead of water. Use the same amount of NaOH.
10. Repeat steps 4-8, instead using 50.0mL of 1.0M HCl, and using 50.0mL of 1.0M NaOH.
Observations:
Combining the water and NaOH creates some bubbles. Combining 1.0M HCl and NaOH turns a litle pink.
Data:
| Reaction 1 |
Reaction 2 |
Reaction 3 |
|
| Mass NaOH |
2.00g |
2.00g |
|
| Mass Total |
102g | 102g | 100g |
| Final Temperature |
25.073 oC |
31.593 oC |
27.357 oC |
| Initial Temperature |
20.675 oC |
20.622 oC |
20.504 oC |
| Change in Temperature |
4.397 oC |
10.972 oC |
6.853 oC |
Calculations:
MassR1= R1=100mL*1.00g/mol=100g +2.00g = 102g
MassR2= 100mL*1.00g/mol=100g +2.00g = 102g
Mass R2= 100mL*1.00g/mol=100g +2.00g R3= 102g
Mass R3= 50mL*1.00g/mol=50g *2=100g
q R1=R1= 4.18*102*4.397 q R1==1875J /1000=1.875kJ
q R2=R2= 4.18*102*10.972 q R2==4678J /1000=4.678kJ
q R3=R3=4.18*100*6.853 q R3==2865J /1000=2.865kJ
ΔH=-q q=-ΔH