Ms November Exam Flashcards

Work through these - it will help you in the exam

1
Q

This is the variable that you change each time you do the experiment

A

the independent variable

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2
Q

The dependent variable is

A

The variable that you measure each time you do the experiment.

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3
Q

The variables you must keep the same each time you do an experiment are called

A

the control variables

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4
Q

To gain more reliable results you

A

repeat your experiment

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5
Q

To make your experiment more accurate

A

you need to improve your method, perhaps by improving the equipment you use, a measuring cylinder would more accurately measure volume than a beaker for example.

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6
Q

To test for oxygen

A

Use a glowing splint, when put in oxygen, it will relight

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7
Q

metal + oxygen

A

͢ metal oxide

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8
Q

magnesium + oxygen

A

magnesium oxide

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9
Q

What is the boiling point of pure water?

A

100 degrees C

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10
Q

What is the melting point of water?

A

zero degrees C

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11
Q

seawater is a mixture, how could you get the salt out?

A

evaporate

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12
Q

chemical test for water

A

anhydrous copper(II) sulfate goes from white to blue

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13
Q

What is chromatorgraphy used for?

A

Paper chromatography is a method for separating dissolved substances from one another. It is often used when the dissolved substances are coloured, such as inks, food colourings and plant dyes

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14
Q

An element

A

A pure substance which cannot be broken down into anything simpler

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15
Q

A compound

A

Two or more elements which are chemically bonded together

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16
Q

A mixture

A

Two or more substances which can be separated.

17
Q

A molecule

A

Two or more atoms joined together

18
Q

Write a word equation for combustion

A

fuel + oxygen͢ carbon dioxide + water. ( A fuel is often a hydrocarbon like methane for example)

19
Q

How can you increase solubility?

A

crush the solute,
stir
Increase the heat

20
Q

How can you get a solute back out of solution?

A

evaporate - for example copper sulfate solution will leave copper sulfate crystals when left to evaporate

21
Q

What does OXIDATION mean?

A

Oxygen has been gained

22
Q

What does REDUCTION mean?

A

Oxygen has been lost

23
Q

What is themal decomposition?

A

A reaction in which a substance is broken down into at least two other substances by heat.
This could happen when potassium permanganate is heated