10S1 Lesson 5/6 - Experimental design

Lesson 1 - What is IGCSE Chemistry?
1 / 23
next
Slide 1: Slide
ChemistrySecondary Education

This lesson contains 23 slides, with interactive quiz and text slides.

time-iconLesson duration is: 55 min

Items in this lesson

Lesson 1 - What is IGCSE Chemistry?

Slide 1 - Slide

  1. Name appropriate apparatus for the measurement of time, temperature, mass and volume, including (a) stopwatches,(b) thermometers, (c) balances, (d) burettes, (e) volumetric pipettes, (f) measuring cylinders, (g) gas syringes
  2. Suggest advantages and disadvantages of experimental methods and apparatus

Slide 2 - Slide

Slide 3 - Slide

Daily Review
timer
2:00
Lightning Question
  • State at least one insight you learned from the video you watched.
  • Write it in your notebook.
The clock's ticking!

Slide 4 - Slide

Slide 5 - Slide

Think about these questions
  • How much can you depend on measurements?
  • Are all measurements trustworthy?
  • How can you tell if it is only an approximation

Slide 6 - Slide

Slide 7 - Slide

The exact number of apples

Slide 8 - Slide

Calibrated into divisions of 1 cm.
Calibrated into divisions of 0.1 cm.

Slide 9 - Slide

Calibrated into divisions of 1 cm.
Calibrated into divisions of 0.1 cm.
What length is measured by Ruler A: 4.2 cm or 4.3 cm?
What length is measured by Ruler B: 4.27 cm or 4.28 cm?

Slide 10 - Slide

REALISATIONS
  • All measurements involve uncertainty.
  • All measurement's last digit is always an estimate.
  • The digits that you record when you measure something are called significant digits.

final, uncertain  digit
sure, certain digits

Slide 11 - Slide

1

Slide 12 - Slide

Watch and Learn
Worked example 1:

  • 4.27 cm has three significant digits.
  • 4 and 2 are certain (sure).
  • 7 is the last uncertain digit.

Slide 13 - Slide

Watch and Learn
Worked example 2:

  • 5.201 g has four significant digits.
  • _______, _______, and _____ are certain (sure).
  • ________ is the last uncertain digit.

Slide 14 - Slide

Watch and Learn
Worked example 3:

  • 27.0 oC has ______ significant digits.
  • _______ and _____ are certain (sure).
  • ________ is the last uncertain digit.

Slide 15 - Slide

2

Slide 16 - Slide

Significant Digits
How many significant digits (SD) are there in:
  • 9.776 g = 4 SD
  • 23.4 kg = _______ SD
  • 208 cm= 3 SD
  • 45 094 mg = _______SD
  • 0.0507 dm3 = 3 SD
  • 0.000000000000071 mol = _______ SD
  • 53 400 km = _______ SD or _____ SD
RULES for Significant Digits
(1) All non-zero digits are significant.

(2) All zeros in between non-zero numbers are significant.

(3) Zeros to the left of a value are NOT significant.

(4) Zeros to the right of a value may OR may not be significant.

Slide 17 - Slide

Slide 18 - Slide


(1) Identify the name of the apparatus.
(2) Read and write the measurement.
(3) Convert the measurement to a given unit.
(4) Identify the number of Significant digits.
timer
5:00

Slide 19 - Open question

Slide 20 - Slide

Slide 21 - Slide

timer
5:00

Slide 22 - Slide

Slide 23 - Slide