LAB REPORT: Measurements
Chemistry Laboratory 101
Date Submitted : July 6, 2009
Group No. 48
Members:
1. Lee, Kim Irish
2. Lovendino, Geraldine
3. Lugtu, Samantha Marie S. (principal author)
Activity 3: Measurements
Objectives:
1. to gain a mastery and comparison on how the Metric and English systems work
2. to establish the proper and efficient usage of measuring devices
3. to measure the properties of matter (mass, length, temperature, et al.) with precision and accuracy
Data Interpretation:
1. The calibration of a foot rule
Interpretation: In a foot rule, measurements of length can be expressed in inches, centimeters as calibrated in the device. To divide an inch in several parts, we should use the fractional form while to divide a centimeter, the decimal form can be considered.
2. Length of laboratory table
Interpretation: Even though the measuring tape and the meterstick provide the same measurement for a certain object, but due to its calibration, the measuring tape is more accurate and hence, it’s better to use than the meterstick. Familiarity with the S&I units can make conversion easier and faster.
3. Dimensions of a book
Interpretation: A foot rule is better calibrated than a meterstick, thus it's more practical to use if we want to have a datum closer to the accepted value. Also, with the use of dimensions; length, width and height, we can already find the area and volume of regular objects through the use of certain formula. Furthermore, the rules for the arithmetic of significant figures should always be mastered and applied to end up with “chemistry-based” results.
4. Parts of the triple beam balance
Interpretation: The parts of the triple beam balance are the following: Degaussed Metal Platforms, Zero/Tare Adjust Knob, Riders, Pointer, Tiered Beams, Advanced Magnetic Dampening System, Metal Bearing Covers, Metal Attachment Weight Points, and Metal Base. . All of these parts contribute to the summation of the balance. We need to know all of these so that we can use the instrument more efficiently, providing accurate and precise measurements with regards to mass.
5. Mass of selected objects
Interpretation: As mass is the amount of matter in an object, we can measure it with the use of balances in this case, the triple beam balance. Although the basic unit for mass is kilogram, we more often use “gram” in chemistry such as this activity.
6. Temperature of selected systems
Interpretation: As defined temperature is the degree of hotness and coldness of an object. With the use of the thermometer, we can measure temperature and express it either in Celsius, Kelvin or Fahrenheit depending on our need. When the temperature drops to 0C, water freezes and when it comes up to 99C or even 100C, water freezes.
Answers to Questions:
1. Compare the data obtained using a foot rule and a meterstick.
-- They have the same measurement but they just partially differ in the number of significant figures. Since the foot rule is well calibrated than the meterstick, its result is more precise or closer to the accepted value than the latter.
2. What is the proper way of taking volume readings of a colorless/clear liquid?
-- Frontally and at eye level, read the lower end if the meniscus when getting the volume of a colorless liquid using a graduated cylinder.
3. Why should volume readings be taken with the eye level parallel to the meniscus?
--This should be done to avoid parallax errors, which are defined in optics as errors in reading an instrument employing a scale and pointer because the observer's eye and pointer are not in a line perpendicular to the plane of the scale.
4. A college freshman 5 feet 4 inches tall and weighing 100 lbs, calculated her body mass index (BMI) to be 17.2. By BMI standard, she is underweight. What are her height and weight equivalents in centimeters and kilograms?
-- Her height and weight are 162.6 cm and 45.35 kg respectively.
A. Sln:
1 ft= 12 in
1 in= 2.54 cm
5 ft X 12 in/i ft X 2.54 cm/1 in
= 152.4 cm
4 in X 2.54 cm/1 in
= 10.16 cm
152.4 cm + 10.16 cm = 162.56 or 162.6 cm
B. Sln:
1 kg= 2.205 lbs
1 lb X 1 kg/2.205 lbs
= 45.35 kg
5. Two patients have been taken their body temperatures - patient A: 99F and patient B: 313 K. If the normal body temperature is 37C, which patient has fever?
--Patient B has fever because his body temperature is expressed as 40.0 C, whereas the temperature of Patient A is only 37.2 C.
A. Sln:
99F to C
F to C
C=5/9 (F - 32)
=5/9 (99F-32C)
=5/9 (67)
=335/9
=37.2 C
B. Sln:
313K to C
K to C
C= K-273
= 313-273
= 40
= 40.0 C
Conclusion/Generalization:
Due to the insufficiency of qualitative observations to make conclusions, scientific observations are quantitatively done and therefore, include measurements. Properties of matter such as length, mass, volume and so forth can be measured and expressed (afterwards converted through the use of “dimensional analysis”) in units of both the English and Metric systems. In a general sense, the metric system is more advantageous, more convenient to use than the English system. Recorded data depends upon and must reflect the accuracy as well as the precision of the measuring devices used. Moreover, a solid background on significant figures and the knowledge on the proper usage of measuring devices help people make reliable conclusions.
-^-<@
Author's Note:
This was my first lab report in chem. My teacher, Sir Pajarito, gave me a 27/30 mark for this paper. You just have to figure out which is right and which is wrong from among my answers. Well, g'luck. LMAO. :)
Date Submitted : July 6, 2009
Group No. 48
Members:
1. Lee, Kim Irish
2. Lovendino, Geraldine
3. Lugtu, Samantha Marie S. (principal author)
Activity 3: Measurements
Objectives:
1. to gain a mastery and comparison on how the Metric and English systems work
2. to establish the proper and efficient usage of measuring devices
3. to measure the properties of matter (mass, length, temperature, et al.) with precision and accuracy
Data Interpretation:
1. The calibration of a foot rule
Interpretation: In a foot rule, measurements of length can be expressed in inches, centimeters as calibrated in the device. To divide an inch in several parts, we should use the fractional form while to divide a centimeter, the decimal form can be considered.
2. Length of laboratory table
Interpretation: Even though the measuring tape and the meterstick provide the same measurement for a certain object, but due to its calibration, the measuring tape is more accurate and hence, it’s better to use than the meterstick. Familiarity with the S&I units can make conversion easier and faster.
3. Dimensions of a book
Interpretation: A foot rule is better calibrated than a meterstick, thus it's more practical to use if we want to have a datum closer to the accepted value. Also, with the use of dimensions; length, width and height, we can already find the area and volume of regular objects through the use of certain formula. Furthermore, the rules for the arithmetic of significant figures should always be mastered and applied to end up with “chemistry-based” results.
4. Parts of the triple beam balance
Interpretation: The parts of the triple beam balance are the following: Degaussed Metal Platforms, Zero/Tare Adjust Knob, Riders, Pointer, Tiered Beams, Advanced Magnetic Dampening System, Metal Bearing Covers, Metal Attachment Weight Points, and Metal Base. . All of these parts contribute to the summation of the balance. We need to know all of these so that we can use the instrument more efficiently, providing accurate and precise measurements with regards to mass.
5. Mass of selected objects
Interpretation: As mass is the amount of matter in an object, we can measure it with the use of balances in this case, the triple beam balance. Although the basic unit for mass is kilogram, we more often use “gram” in chemistry such as this activity.
6. Temperature of selected systems
Interpretation: As defined temperature is the degree of hotness and coldness of an object. With the use of the thermometer, we can measure temperature and express it either in Celsius, Kelvin or Fahrenheit depending on our need. When the temperature drops to 0C, water freezes and when it comes up to 99C or even 100C, water freezes.
Answers to Questions:
1. Compare the data obtained using a foot rule and a meterstick.
-- They have the same measurement but they just partially differ in the number of significant figures. Since the foot rule is well calibrated than the meterstick, its result is more precise or closer to the accepted value than the latter.
2. What is the proper way of taking volume readings of a colorless/clear liquid?
-- Frontally and at eye level, read the lower end if the meniscus when getting the volume of a colorless liquid using a graduated cylinder.
3. Why should volume readings be taken with the eye level parallel to the meniscus?
--This should be done to avoid parallax errors, which are defined in optics as errors in reading an instrument employing a scale and pointer because the observer's eye and pointer are not in a line perpendicular to the plane of the scale.
4. A college freshman 5 feet 4 inches tall and weighing 100 lbs, calculated her body mass index (BMI) to be 17.2. By BMI standard, she is underweight. What are her height and weight equivalents in centimeters and kilograms?
-- Her height and weight are 162.6 cm and 45.35 kg respectively.
A. Sln:
1 ft= 12 in
1 in= 2.54 cm
5 ft X 12 in/i ft X 2.54 cm/1 in
= 152.4 cm
4 in X 2.54 cm/1 in
= 10.16 cm
152.4 cm + 10.16 cm = 162.56 or 162.6 cm
B. Sln:
1 kg= 2.205 lbs
1 lb X 1 kg/2.205 lbs
= 45.35 kg
5. Two patients have been taken their body temperatures - patient A: 99F and patient B: 313 K. If the normal body temperature is 37C, which patient has fever?
--Patient B has fever because his body temperature is expressed as 40.0 C, whereas the temperature of Patient A is only 37.2 C.
A. Sln:
99F to C
F to C
C=5/9 (F - 32)
=5/9 (99F-32C)
=5/9 (67)
=335/9
=37.2 C
B. Sln:
313K to C
K to C
C= K-273
= 313-273
= 40
= 40.0 C
Conclusion/Generalization:
Due to the insufficiency of qualitative observations to make conclusions, scientific observations are quantitatively done and therefore, include measurements. Properties of matter such as length, mass, volume and so forth can be measured and expressed (afterwards converted through the use of “dimensional analysis”) in units of both the English and Metric systems. In a general sense, the metric system is more advantageous, more convenient to use than the English system. Recorded data depends upon and must reflect the accuracy as well as the precision of the measuring devices used. Moreover, a solid background on significant figures and the knowledge on the proper usage of measuring devices help people make reliable conclusions.
-^-<@
Author's Note:
This was my first lab report in chem. My teacher, Sir Pajarito, gave me a 27/30 mark for this paper. You just have to figure out which is right and which is wrong from among my answers. Well, g'luck. LMAO. :)
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