Download presentation

Presentation is loading. Please wait.

1
**Chemistry: SI Units & Conversions**

2
**SI Base Units of Measure commonly used in chemistry**

Time: second (s) Length,distance: meter (m) Mass: kilogram (kg) In class, we consider the “base unit” to be grams. Volume: liter (l) Temperature: Kelvins (K) note: no degree symbol In chemistry lab, we use the Celsius temperature scale. ( °C)

3
Derived Units A derived unit is one in which the units are combined mathematically. Volume: cubic centimeter (cm3) (cm x cm x cm) Area: square meter (m2) ( m x m) Density: mass volume

4
**Converting Celsius to Kelvin**

Kelvins = C + 273 °C = Kelvins - 273

5
**Prefixes for SI Units Prefixes for units smaller than 1:**

micro () 1 X 10-6 or milli (m) 1 X or centi (c) 1 X 10-2 or deci (d) 1 X 10-1 or Prefixes for units larger than 1: kilo (k) 1 X 103 or 1,000

6
**Conversion Using the Factor-Labeling Method : (Dimensional Analysis)**

Starting unit Target unit Problem: Convert cm to m = X Step 1: write down the starting measurement: number and unit! Step 2: Convert from this prefix to the base unit. (This means meters, liters or grams.) Step 5 If you have arrived at the target unit, you are done! Be sure to include the unit and significant figures in your answer! Step 3: Cancel the units that divide each other out. Step 4: Perform the math… divide by the numbers on the bottom, multiply by the numbers on the top!

7
**Practice! Convert 0.00450 km to cm ? X X =**

The correct answer is 450 cm, but that’s only 2 sig figs…. ????? Use scientific notation to correct the sig figs! 4.50 x 102 cm

Similar presentations

© 2021 SlidePlayer.com Inc.

All rights reserved.

To make this website work, we log user data and share it with processors. To use this website, you must agree to our Privacy Policy, including cookie policy.

Ads by Google