Chapter 11, Problem 11.53P

Interpretation Introduction

Interpretation:

• Using the buoyancy correction and density the number of grams of tris that was weighed has to be determined.
• Whether the buoyancy correction introduce random or systematic error in the molarity calculated for $HCl$ using tris has to be ascertained. 
• The magnitude of error has to be expresses in percentage. 
• The calculated molarity and true molarity of $HCl$ has to be compared.

Concept introduction:

Air has buoyancy due to which an object weighs less in air than and it is not same as it does in vacuum.  Buoyancy correction is made to obtain the accurate measurement of the object weighed which is the difference between density of the object and density of the weights that have been used to calibrate the balance.

Molarity is one of the parameters used to express concentration of a solution.  It is expressed as,

$\text{Molarity = }\frac{number\text{ of }molesof\text{ solute}}{volume\text{ of solution in L}}$

Random errors are errors in experimental measurements due to unknown and unexpected alterations in the experiment caused by surrounding conditions of the instrument.

Systematic errors are errors caused by inappropriate handling of instruments.

Percentage error is calculated as,

$\%\text{ error}\text{= }\frac{theoretical\text{ value - experimental value}}{theoretical\text{ value}}\times 100$