01.07 Accuracy and Precision: Balance Lab Worksheet
Before You Begin: You may either copy and paste this document into a word processing program of your choice or print this page. Procedure
Access the virtual lab and complete the experiments.
Data
* Below is the table that you will complete for the virtual lab. Either type your results into this table or print the table from the virtual lab (it must be submitted to receive full credit for this assignment.) * To print from the virtual lab.

1. Be sure the data table is viewable.
2. Right-click (PC) or Command-Click (Mac) on the table and select print. Part I: Density of Unknown Liquid|
| Trial 1| Trial 2| Trial 3|
Mass of Empty 10 mL graduated cylinder (grams)| 25.31| 25.32| 26.03| Volume of liquid (milliliters)| 8.12| 8.22| 8.52 | Mass of graduated cylinder and liquid (grams)| 35.41| 36.01 | 36.41 | Part II: Density of Irregular-Shaped Solid|

Mass of solid
(grams)| 42.35| 40.65| 40.95|
Volume of water (milliliters)| 48.92| 50.03| 50.04 | Volume of water and solid (milliliters)| 53.93| 55.04| 55.05| Part III: Density of Regular-Shaped Solid|
Mass of solid (grams)| 25.95| 27.66 | 25.67 |
Length of solid (centimeters)| 5.25| 5| 4.50|
Width of solid (centimeters)| 3| 4| 3.50|
Height of solid (centimeters)| 2.50| 3| 2|
Calculations
Show all of your work for each of the following calculations and be careful to follow significant figure rules in each calculation. Part I: Density of Unknown Liquid
1. Calculate the mass of the liquid for each trial. (Subtract the mass of the empty graduated cylinder from the mass of the graduated cylinder with liquid.) * Trial 1: 35.46-25.3=10.16

* Trial 2: 36.01-25.39=10.62

* Trial 3: 36.41-26.03=10.38
2. Calculate the density of the unknown liquid for each trial. (Divide the mass of the liquid calculated above by the volume...

...01.07Accuracy and Precision: BalanceLabWorksheet
Data
* Below is the table that you will complete for the virtual lab. Either type your results into this table or print the table from the virtual lab (it must be submitted to receive full credit for this assigment.)
* To print from the virtual lab.
1. Be sure the data table is viewable.
2. Right-click (PC) or Command-Click (Mac) on the table and select print.
Part I: Density of Unknown Liquid |
| Trial 1 | Trial 2 | Trial 3 |
Mass of Empty 10 mL graduated cylinder (grams) | 25.50 | 25.50 | 25.50 |
Volume of liquid (milliliters) | 8.10 | 8.30 | 8.10 |
Mass of graduated cylinder and liquid (grams) | 35.50 | 36.00 | 35.50 |
Part II: Density of Irregular-Shaped Solid |
Mass of solid (grams) | 38.285 | 42.345 | 42.577 |
Volume of water (milliliters) | 51.00 | 50.95 | 52.90 |
Volume of water and solid (milliliters) | 55.50 | 55.90 | 56.95 |
Part III: Density of Regular-Shaped Solid |
Mass of solid (grams) | 27.00 | 26.50 | 25.50 |
Length of solid (centimeters) | 5.25 | 5.00 | 4.50 |
Width of solid (centimeters) | 3.00 | 4.00 | 3.50 |
Height of solid (centimeters) | 2.50 | 3.00 | 2.00 |
Calculations
Show all of your work for each of the following calculations and be careful to follow significant figure rules in each calculation.
Part I:...

...Precision describes the closeness of results that have been obtained in exactly the same way while accuracy indicates the closeness of the measurement to its true value. This experiment was used to determine the accuracy and precision of different volumetric measuring devices, as well as determining the density of an unknown metal. This lab was to help understand the application to volumetric measurements.
Part 1:
First, the next-to-smallest beaker was cleaned, dried, and weighed on the scale where it’s mass was determined. The container was then tared so the scale would only read the mass of the water. The smallest beaker was used to measure out 14 mL of water. Then, that waster was poured into the pre-weighed beaker and put on the scale. Once the measurement was recorded the beakers were both cleaned and dried. This process was repeated two more times.
Second, a 100 mL graduated cylinder was used to measure out 14 mL of water. Then, that water was poured into the pre-weighed beaker and put on the scale. Once the measurement was recorded, the beaker and graduated cylinder were both cleaned and dried. This process was repeated two more times.
Third, a 25 mL buret was used to measure out 14 mL of water. Then, that water was poured into the pre-weighed beaker and put on the scale. Once the measurement was recorded, the beaker and buret were both cleaned and dried. This process was repeated two...

...Lab No.1: density, accuracy and precision
Aim: to determine the relative precision and accuracy of different glassware items by calculating the density of a known substance.
Introduction: the density of a substance is its mass per unit volume. (where P-density, m- mass and v- volume). Different materials usually have different densities and densities vary according to the pressure, temperature and purity of a substance. When measuring, there is always a small uncertainty or error and therefore no measurement is exact.
Variables:
Independent: the type of liquid used
Dependant: the volume and density of the liquid
Controlled: the same type of beaker as the mass of the beaker is never changed
Hypothesis : the larger the divisions on the glassware items the bigger the percentage of error.
Materials:
Car oil
Coke Zero
Liquid soap
Salty water
1x 200ml beaker
1 x 100ml beaker
1 x 10ml cylinder
1 x weighing scale
1 x thermometer
Procedure:
1. Weigh a dry 100 ml beaker, a 10 ml graduated cylinder and a 10 ml pipette (in this case weigh a 150 ml beaker that you will transfer into a pipette, pipettes cannot be weighted effectively) and record the mass for each case. Do not forget that trailing zeros are significant figures and should be recorded.
2. Obtain a fair amount of water and measure its temperature.
(Remember here some students are measuring different substances, so the...

...Erica Alonso
Chemistry Honors 1
Mr. Cunningham
1.07 Accuracy and Precision
Procedure
Access the virtual lab and complete the experiments.
Data
• Below is the table that you will complete for the virtual lab. Either type your results into this table or print the table from the virtual lab (it must be submitted to receive full credit for this assignment.)
Part I: Density of Unknown Liquid
Trial 1 Trial 2 Trial 3
Mass of Empty 10 mL graduated cylinder (grams) 26 25.6 26
Volume of liquid (milliliters) 8.6 8.7 8.5
Mass of graduated cylinder and liquid (grams) 36.5 36.5 36.7
Part II: Density of Irregular-Shaped Solid
Mass of solid
(grams) 38.384 41.435 41.951
Volume of water (milliliters) 51 50 52
Volume of water and solid (milliliters) 57 55 58
Part III: Density of Regular-Shaped Solid
Mass of solid (grams) 28.1 26.1 26.2
Length of solid (centimeters) 5.25 5 4.5
Width of solid (centimeters) 3 4 3.5
Height of solid (centimeters) 2.5 3 2
Calculations
Show all of your work for each of the following calculations and be careful to follow significant figure rules in each calculation.
Part I: Density of Unknown Liquid
1. Calculate the mass of the liquid for each trial. (Subtract the mass of the empty graduated cylinder from the mass of the graduated cylinder with liquid.)
Trial 1- 10.5
36.5-26= 10.5
Trial 2- 10.9
36.5-25.6= 10.9
Trial 3- 10.7
36.7-26= 10.7...

...
Experiment
Density, Accuracy, Precision And Graphing
OBJECTIVES
1. The determination of the density of water
2. A comparison of the accuracy and precision of a graduated cylinder and a pipet
EXPERIMENTAL MATERIALS
Part A
A 50mL graduated cylinder
A balance
50.0mL deionized water
A rubber policeman
Part B
A 100mL beaker
A 50mL graduated cylinder
A volumetric pipet
120.0mL deionized water
A thermometer
A rubber policeman
EXPERIMENTAL METHODS
Part A: Density of water
1. An empty, dry 50mL graduated cylinder was obtained.
2. The mass of graduated cylinder with using a balance.
3. 10.0mL of deionized water was added to the 50mL graduated cylinder.
4. Mass of 10.0mL of deionized water + the cylinder was measured with balance.
5. To take only mass value of the 10.0mL deionized water, the mass value of the graduated cylinder was subtracted from the mass value of the 10.0mL of deionized water + the cylinder.
6. Density of 10.0mL of deionized water was calculated by its’ mass and volume. (d=m/v)
7. The exact density of the 10.0mL of deionized water was recorded on the data sheet.
8. Deionized water was added up to the 30.0mL mark of the 50mL graduated cylinder and Steps 3 to 7 were repeated for 30.0mL.
9. Deionized water was added up to the 50.0mL mark of the 50mL graduated cylinder and...

...Experiment #4
Weighing and Volumetric Techniques – Accuracy and Precision
Abstract
The purpose of this experiment is to become familiar with proper techniques for using the analytic balances, graduated cylinder, burette and pipette and determine which is more accurate and/or precise. In this experiment, the burette and pipette were more exact than the graduated cylinder and the analytic balance gave a very accurate and precise answer.
Results / Report
1) Weighing Copper
Copper sample #: 1
Balance #: 14
Temperature: 22.8EC
Weighing Attempt # Mass of Copper Sample (g)
1 3.1234
2 3.1233
3 3.1235
4 3.1232
Average Mass
= (3.1234g + 3.1233g + 3.1235g + 3.1232g) ÷ 4
=3.1234g
Standard Deviation
( - ) ( - )
3.1234 0 0
3.1233 -
3.1235
3.1232 -
Σ =
Or 0.0001
2) Burette Readings
a) Graduated Cylinder b) Pipette
Initial Volume (mL) 44.72 44.91
Actual amount added (mL) Actual amount added (mL)
1st 34.81 9.91 1st 34.98 9.93
2nd 24.90 9.91 2nd 25.00 9.98
3rd 15.05 9.85 3rd 15.08 9.92
Graduated Cylinder average
( 9.91±0.01 mL + 9.91±0.01 mL + 9.85±0.01 mL ) ÷ 3
= 9.89±0.03 mL
Pipette average...

...BalanceLab of a Copper Slug and Sodium Chloride (NaCl)
on a Centigram and Electronic Scale
PURPOSE/INTRODUCTION
The purpose of this experiment is to learn how to weigh a substance on a centigram scale and an electronic scale through direct weight or by weight difference. The hypothesis is that all scales used should show the same weight for a given sample. The experiment should show precision and accuracy of the equipment being used. This will allow a better understanding on how to properly weigh a given sample and what scale is more accurate.
The following are definitions of terms used:
Precision refers to the closeness of the set of values obtained from identical measurements of a given quantity.
Accuracy refers to the closeness of a single measurement to its true value.
To determine the difference between two measurements the following formula was used:
Δ Weight = Weight A – Weight B (1)
To determine the average of all the weights the following formula was used:
a = ∑X1 + X2 + X3 +…XnXn (2)
MATERIALS
Materials required to test the hypothesis in a lab include:
*
* Centigram Balance (Qty. 2)
* Electronic Balance (Qty. 1)
* Beaker, 100 mL (Qty. 1)
* Watch Glass (Qty. 1)
* Copper Slug (Qty. 5)
* Unknown Mass (Qty. 1)
* Sodium Chloride (1.0 to 1.2g)
METHOD
Part One: To find the direct...