4. Quality of observations/data 

 Consistent data 
At least two trials are consistent with expectations. 
 Accurate measurements, observations 
Measurements are +/ 3.0 mL 
 Completed data table 
All trials performed and data recorded. 
 Correct units 
Volumes labelled as mL or L. 
 Qualitative description 
Indicator is identified. 
5. Graph 
Not required for this task. 
 Curve is appropriate to data trend 

 Points plotted accurately 

 Appropriate scale 

 Axes labelled with variabls 

 Variables placed on correct axes 

6. Calculations 

 Calculated accruately 
Calculations are complete and mathematically
correct. 
 Substituted correctly into relationship 
Moles of neutralizing solution are used to find
molarity unknown solution. 
 Relationship stated or implied 
Volume of neutralizing solution is converted
to moles. 
 Units used correctly 
mL correctly converted to L. 
 Use all data available 
Calculations are performed on all generated
data; reason stated if data is excluded. 
7. Conclusion 

 Consistent with scientific principle 
Conclusion based on student's data is consistent
with identity and concentration of unknown solution. 
 Sources of error 
* 
 Consistent with data 
Unknown solution is identified as an acid or
a base and concentration is determined, based on student's
data.(1) 
 Relationship among variables stated 
Unknown solution is neutralized by acid or base
used as titrating solution. 
 Variables stated in conclusion 
Unknown and acid or base (neutralizing solution)
are mentioned here. 