sc 9 unit d 1.4 notes student filled...

sc 9 unit D 1.4 notes student filled in.notebook

1

SECTION 1.4 Cells and Batteries ( p 288 294)_______________________: a package of chemicals that produces small amounts of chemical energy

2. secondary cells _______________ the chemical reactions can be ___________ by plugging in to an electrical source

ex. NiCad batteriescar batterycell phone and IPOD batteries

There are two types of cells:

1. primary cells ________________ once the chemicals are used up, the reaction cannot be reversed

ex. __________ regular AA, AAA, C, D

DRY CELLS: ___________ to prevent leaking

chemicals are in a ______ _______ called an _____________, which conducts electricity

the two terminals, called ___________, are made of two _________ metals (sometimes one is carbon)

when the electrolyte ______ with the electrodes, one becomes positive and the other becomes negative.

negative electrode: where electrons ______

positive electrode where electrons _______

most common type of dry cell = ___________________ relatively cheap good shelf life good electricity output reliable leak resistant


2

WET CELLS: the electrolyte is a ________ which is usually an _______ requires two ____________ metal electrodes used in cars, motorcycles, and wheelchairs

car battery: electrolyte is _______________ has ____________ positive and

negative metal plates

a simple wet cell:

electronselectrons

One electrochemical cell is called a ______.

A ____________is two or more cells connected together.

The voltage of the battery changes depending on how many cells are connected and whether they are connected in series or in parallel.

In parallel, the voltage is the same as ____ cell, but the battery lasts ________.

In series, the voltages of each cell _________, to make a higher voltage battery.


3

HISTORY OF ELECTROCHEMISTRY

_____________________: the study of chemical reactions involving electricity

1800 first practical battery made by Alessandro ______: layered copper and zinc discs and separated with electrolyte soaked paper

1807 Davy linked 2000 cells together to form a massive battery

APPLICATIONS OF ELECTROCHEMISTRY:

1. 2. 3. 4.

1. electrolysis: using electricity to ______ molecules into their _________Example: splitting water makes _____________

H2O(l) > H2 (g) + O2 (g) when pure H2 gas and pure O2 gas are mixed and ignited, massive amounts of ________ is released

2. electroplating: ______________________ with a thin layer of gold or silverExamples: silver plated spoons gold plated jewelry chrome plated iron or steel (to prevent rusting)

3. anodizing: ________________ with aluminum oxide to _____________ it Examples: screen doors airplane or car parts

4. electrorefining: _________________________ from metalExample: used in processing very pure gold


4

QUESTIONS:1. a) Label the following two cells using these words:

carbon rod lead plate plastic insulatorelectrolyte negative terminal positive terminal

b) What is the main difference between two types of cells?

2. Why do dry cells eventually stop working?

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3. a) What is another name for a rechargeable cell? ___________________ b) How does a rechargeable cell work?

4. What is an electrolyte?

5. This 6 V lantern battery contains 4 1.5 V cells. Are these cells connected in series or parallel?

_____________

What is the voltage of this battery of 1.5 V cells connected in series?

__________

6. A car designer has proposed a new car battery. She is planning to test the following electrode combinations. Which ones will not work? Explain. a) both zinc b) zinc & copper c) both copper d) zinc and carbon

7. Match the following:___ 1. electroplating a. coating aluminum to make it stronger___ 2. anodizing b. using electricity to break molecules into elements___ 3. electrorefining c. used to purify metals___ 4. electrolysis d. coating cheaper metals with more expensive metals

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