Chem Lab #2

Volume & Density

Pre Lab: Page 1

• I Purpose – Measure the volume of a quantity of water in 3

different graduated cylinders.– Determine the density of aluminum.

• II Materials– 3 graduated cylinders: 10 mL, 50 mL, and 100 mL,

Bunsen burner, striker, Harvard trip balance, ruler, aluminum bar.

Pre Lab Page 2 (draw 2 tables ONLY so that data can be entered when you do the lab)– VI Data – draw tables NEATLY with a ruler (in tray)

and label. These are the headings, you draw the tables.

– Volume:

Volume, mL (include estimated value to show sig fi

LEAVE 3 spaces….

Density of Al:

Volume 1st trial (mL) 2nd trial (mL) 3rd trial (mL

10-mL

50-mL

100-mL

Trial Mass Volume Vo Va % Error

(g) (cm3) (g/cm3) (g/cm3) %

#1 2.6989

#2 2.6989

#3 2,6989

Procedures:Volume:Place approximately 10 mL of water in the smallest graduated cylinder. Measure (estimating the last digit) and record in the data table.Pour the same water into the 50 mL graduated cylinder. Get as much water off the sides and into the bottom as possible. Measure and record in the data beneath the last reading.Repeat, using the same water being poured into the largest grad. Cylinder.Repeat this entire process two more times for two more trials.Density:Measure and record the mass of the aluminum bar using the scales.Measure the length, width, and height of the Al bar and record each measurement.Determine the volume using V = lwhDetermine your observed value (Vo) for the density using: D = m

VDetermine your percent error using Va given in the table.Repeat for density two more times, if possible.

Page 3

Show each formula. Put in your values with units. Solve and write answers with units.–VIII Calculations – show, formula, math, and

answer with units.V = lwh = 7.58cm(2.50cm)(1.21cm)V = 22.92= 22.9cm3

Vo = D = m/v% Error = /Vo-Va/ x 100% =

Va

Reminders

• A person – aprons (get, each fold your own, but A puts away)

• B person – gets goggles and puts them away for the group

• If any items (equipment, trash, etc.) are left behind for me to clean up, each person in your group loses 1 point on the lab grade.

Individual report must include & be stapled together:

• P. 1: Prelab I, II.• P. 2: VI (tables completed) • P. 3: VIII Calculations (formulas, work, and

answers with units and answers entered in tables).

• P. 4: X Conclusion (2 statements). See lab write up handout to give you ideas of what to say.

Lab Report Expectations

• DO NOT WRITE on the back of any sheet• Staple your own report papers together (make

sure your name is on top sheet and that you have 4 sheets)

• Hand in your group’s reports in a stack (ABC by last name) BEHIND one cover sheet

• Paper clip the stack• ONLY 1 report from the group will be graded