- 58 Views
- Uploaded on
- Presentation posted in: General

Appendix 1 - Measurements

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

- We makeQUALITATIVEobservations of reactions — changes in color and physical state.
- We also makeQUANTITATIVE MEASUREMENTS, which involve numbers.
- UseSI units—(International System of Units) based on the metric system

When we measure, we use a measuring tool to compare some dimension of an object to a standard.

For example, at one time the standard for length was the king’s foot. What are some problems with this standard?

Which tool(s) would you use to measure:

A. temperature

B. volume

C. time

D. weight

Match L) length M) mass V) volume

____ A. A bag of tomatoes is 4.6 kg.

____ B. A person is 2.0 m tall.

____ C. A medication contains 0.50 g Aspirin.

____ D. A bottle contains 1.5 L of water.

M

L

M

V

Based on:

- number

- units

- accuracy report

S.I. Units are:

- related by factors of 10

* Table C of Reference Tables

3

3

- Kilo- 10 or 1 kilometer = 10 m
1 km or 1000 m

10 m 1 km

- Centi- 10 or 100 centimeters = 1 meter
100 cm or 1 m

1 m 100 cm

- Milli- 10 or 1000 mm
1 m

3

-2

-3

- Length = meter (m)
- Mass = kilogram (kg) also gram (g)

Mass vs. Weight

Mass: Amount of Matter

Weight: Force exerted by the mass, only present with gravity

- Kelvin (K)
- Measure of the average kinetic energy
*Thermometer is a molecular speedometer. Shows vibrational energy.

- Table T of
Reference Tables

The base unit for time = seconds (s)

60 seconds = 1 minute = 1/60 hour

- Measured in moles (mol)
- Contains Avogadro’s number of particles
- 6.02 X 10
- 602,000,000,000,000,000,000,000

23

- Liter (L)
- Volume = L X W X H
- 1cm X 1cm X 1cm = cm or 1ml
- 1dm X 1dm X 1dm = dm or 1L

3

3

- Joules (J)
- 4.18 J = the energy needed to raise the temperature of 1 gram of water 1 degree K.
- Table B of Reference Tables – Specific Heat of Water
Heat (q) = 4.18J/gK X g (water) X t

- Suppose that a calorimeter contains 200. grams of water at 294.0 K. As an exothermic reaction occurs the water temperature rises to 314.0 K.
- What is the quantity of heat transferred?
- Temperature change of 20.0 K for 200g water.
- q= 4.18 J/gK X 200g X 20.0 K
- q= 16,720 J or 16.7 KJ
1 calorie = 4.18 Joules

- Pascal (Pa)
- Pa = force
unit area

- Table A of Reference Tables
- 1 atm = 101.3 kPa

- Table T of Reference Tables
- Solve for m
D X V = m

- Solve for V = m
D

- What is the density of an object with a mass of 20.1g and a volume of 142.5cm ?
- What is the mass of an object with a density of 32.1 g/cm and a volume of 10.0cm ?
- What is the volume of an object with a mass of 40g and a density of 10g/cm ?

3

3

3

3