# General Chemistry

Review Sheet for the Midterm

### First and foremost, use the previous review sheets!!!!!!=

For up to an additional 10 points on the exam, fill out the form on the last page as you study for the exam and present it to me when we take the exam.

## TOPICS and Practice

Significant Figures/Digits

When data is measured, we must compose the number in such a way that indicates how accurate the instrument can measure.

ie: an instrument that can be used to measure a mass as 30.000g is more accurate than one that can do it as 30.0g.

How to count significant figures/digits – Follow the Atlantic Pacific rule

Practice: How many significant figures are in the following numbers?

1. 34345 = _________

2. 5.03 = _________

3. 420 = ________

Review Sheet for the Midterm

When we then use these numbers in arithmetic, the final product can only be expressed in line with the least significant figure. You may have to round the number to make it work.

How many significant figures need to be in the produce of:

1. 30 x 20.01 =

2. 0.002 divided by 10.34

Density - Density is a comparison between the mass of a substance and it’s volume.

Every pure substance has its own unique density that can be used to confirm its identity

At times you may have to use a graduated cylinder to determine the volume of an irregularly shaped substance.

D=M/V

What is the volume of the object in the graduated cylinder? ______

Calculate the density of the object if the mass is

6g. ________g/mL

% Error

Observed Value – Accepted Value

% Error = -------------------------------------------- x 100

PRACTICE PROBLEM

Accepted Value

Calculate the % Error of a measurement that should have been 5g, but instead was 50g.

Review Sheet for the Midterm

Instruments NAME THE INSTUMENTS AND WHAT THEY ARE USED FOR

Matter – Use the other review sheet for the bulk of this material

Particle Diagrams

Draw a particle diagram showing a pure compound in gas from

Draw a particle diagram showing a mixture of a

Diatomic element and a compound in solid form

In terms of particles state what happens when a solid substance absorbs energy.

The particles will _________________________

Is this endothermic or exothermic? _______________ Why?

Review Sheet for the Midterm

Atomic Theory

The way scientists view the atom has changed over time. Complete the chart below.

Which part of the atom is now better

Scientist Model The Experiment understood?

Illustration

JJ Thomson

Earnest Rutherford

Neils Bohr

X

The Modern Model

Wave Mechanical

Model

X

X

Review Sheet for the Midterm

Study Log

Name: ______________ Period: ______

Study Plan: How do I plan on studying for this exam?

Date of the Exam: _________

Identify dates, times and topics you plan on addressing

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

Date

_________________________________________________________________

Start time End time List things you understand better

List the resources used.

Review Sheet for the Midterm