Chemistry Flashcards Part 2

Question 1

What is fractional distillation?

Answer 1

It is used to separate two or more liquids that have been mixed together

Question 2

What is the method of simple distillation?

Answer 2

The solution is heated and a liquid evaporates producing vapour, the vapour passes through the condenser, where it cools and condenses, turning into the pure liquid into the beaker.
After all the liquid has been collected the solid solute is left behind.

Question 3

What was JJ Thompson’s theory?

Answer 3

JJ Thompson proposed atoms were in a plum pudding structure.
He suggested that the atom was a positively charged sphere with negative stuck into it.

Question 4

What was John Dalton’s theory

Answer 4

Dalton proposed that atoms were solid spheres.
He suggested that compounds/molecules could be broken down into separate spheres

Question 5

Properties of an impure substance (Two)

Answer 5

• Mixture of two or more elements or compounds.
• They melt and boil over a range of temperatures

Question 6

What activities lead to the increase of greenhouse gases? (Three)

Answer 6

• Carbon dioxide produced during combustion of fossil fuels in power stations and cars
• Deforestation causes less CO2 to be taken in by photosynthesis
• Methane is produced and released from landfill sites as waste decomposes

Question 7

How is carbon monoxide formed?

Answer 7

Incomplete combustion of hydrocarbons

Question 8

What is the formula for Alkenes

Answer 8

CnH2n

Question 9

Properties of pure substances (Two)

Answer 9

• Substance containing just one element or one compound.
• Identified using its fixed points

Question 10

Test for chlorine

Answer 10

Damp blue litmus paper turns white

Question 12

What is the greenhouse effect? (Three)

Answer 12

• The sun emits short-wave electromagnetic radiation e.g. UV which warms the Earth
• The Earth loses heat by emitting long-wave radiation e.g. thermal radiation.
• Greenhouse gases in the atmosphere absorb some of this long-wave infrared and radiates in all directions (keeps the Earth the correct temperature).

Question 14

What is the formula to find the Rf value?

Answer 14

Distance moves by substance ÷ Distance moved by solvent.

Question 15

What is the method of fractional distillation?

Answer 15

The solution is heated to the temperature of the substance with the lowest boiling point.
The substance will rise and evaporate first, vapours go through a condenser where they cool and condense into a liquid into a beaker.
This will leave behind the other components in the mixture.

Question 16

What is the process involving the mobile phase and stationary phase?

Answer 16

The mobile phase moves through the stationary phase, carrying the components of the mixture under investigation. Each component in the mixture will have a different attraction for the mobile and stationary phase.

Question 17

What are the definitions of:
a). Alkalis
b). Neutral substances

Answer 17

• Alkalis are a specific group of bases that are soluble in water, they are soluble hydroxides. e.g. sodium hydroxide solution
• Neutral substances are substances that are neither acids nor bases. e.g. water

Question 18

What is chromatography?

Answer 18

Used to separate and identify mixtures of amino acids

Question 19

What is a formulation? (Two)

Answer 19

• A formulation is a mixture that has been designed to produce a useful product e.g. medical drugs, paint.
• Other formulations are: fuels, alloys, fertilisers, pesticides, cosmetics and some food products.

Question 20

What is simple distillation?

Answer 20

It is used to spearate a mixture where the solid has dissolved and so a solution has formed

Question 21

Colour change from alkane water + bromine water

Answer 21

Stays orange

Question 22

Ethene
No. of carbons:
No of hydrogens:
Formula:
Structure:

Answer 22

• 2 carbons
• 4 hydrogens
• CnH2n
• C=C - H - H - H - H

Question 23

What are alkenes? (Three)

Answer 23

• Family of hydrocarbons
• Each contains one carbon-carbon double covalent bond
• Double bond = unsaturated

Question 24

Why do we do cracking? (Two)

Answer 24

• Smaller alkanes (C-C single bonds) are useful as fuels.
• The alkene (one C=C double bond) produced can be made into polymers and used as plastics

Question 25

Where are most metals found?
What are ores?
How do you extract metals from their ores?

Answer 25

• Most are found in ores chemically bonded to other elements
• Ores are rocks from which it is economically viable to extract the metals that they contain
• The metal must be reduced by having the oxygen removed

Question 26

What is the reactivity series?

Answer 26

A list of metals in order of their reactivity with the most reactive metals at the top, and the least reactive metals at the bottom

Question 27

How can we put metals in order of reactivity? (Two)

Answer 27

• Reacting metals with water
• Reacting metals with dilute acid

Question 28

How do you react metals with water? (Three)

Answer 28

• Put 4 clean test tubes in a test tube rack
• Put 1 spatula of copper (no more) into one of the test tubes. Repeat with the 3 other metals. You should have four test tubes containing a spatula of each of 4 different metals at this point.
• Using a wash bottle, half fill each test tube with water

Question 29

What is the definition of:
Acids?
Bases?

Answer 29

• Substances that taste very sour (although many are far too dangerous to be put in your mouth( Hydrochloric acid, sulfuric acid, nitric acid, ethanoic acid (vinegar and citric acid)
• Bases are substances, including alkalis which can neutralise acids. Metal oxides and metal hydroxides are bases.

Question 30

What do acids do during dissociation?
What type of acids dissociate more?

Answer 30

• Acids donate/release H+ ions (hydrogen ions) when in solution - this is dissociation.
• Strong acids dissociate into ions more than weak acids do.

Question 31

What is electrolysis?

Answer 31

The breaking down of an ionic compound using electricity

Question 32

What are ionic compounds?

Answer 32

• Compounds made when metals + non-metals react together
• They are made of oppositely charged ions, and are held together by strong electrostatic bonds.