LAB OVERVIEW

HOW TO READ A GRADUATED CYLINDER?

mL

We report a measurement by recording

ALL the certain digits + ONE uncertain digit

Significant Figures

(except leading zeros. more details in a minute.)

10-mL graduated cylinder: 2 decimal places;

25-mL graduated cylinder: 2 decimal places;

100-mL graduated cylinder: 1 decimal place.

PURPOSE

DETERMINE THE ACCURACY OF 4 VOLUMETRIC TOOLS

BEAKER

GRADUATED CYLINDER

PIPET

BURET

PERCENT ERROR

WHERE:

EXP = EXPERIMENTAL VALUE

THE = THEORETICAL VALUE

EXP THE 100 %

THE

% ERROR =

BEAKER: 25 mL

GRADUATED CYLINDER: 25.00 mL

PIPET: 25.00 mL

BURET: 2x.xx mL

HOW TO FIND EXPERIMENTAL VALUES?

HOW TO FIND THEORETICAL VALUES ?

• V = m/d

• d ─ MEASURE WATER TEMPERATURE, THEN READ FROM APPENDIX H.

• m ─ MEASURE FROM A BALANCE. USE A BEAKER (EXCEPT GRADUATED CYLINDER) TO CARRY YOUR WATER SAMPLE TO THE BALANCE.

BALANCE TIPS

• USE THE SAME BALANCE

• SOLID OBJECTS ONLY ON BALANCE PAN

• USE CONTAINER FOR LIQUIDS/POWDERS

• POUR LIQUIDS & POWDERS AWAY FROM BALANCE

• ZERO BALANCE (ZERO OR 0/T BUTTON) BEFORE EACH MEASUREMENT

EXPERIMENT #2

• ORDER OF MEASUREMENTS

• CLEAN YOUR BENCH AREA AND ASK FOR INSPECTION BEFORE LEAVING. SQUEEZE BOTTLE AND PAPER TOWEL.

EXPERIMENT #2

QUESTIONS?