Module 2 Flashcards
Who was the first modern person to take atoms seriously?
John Dalton
Who is often regarded as the father of atomic theory?
Democritus
Who put forward the plum pudding model?
JJ Thomson
What is the plum pudding model?
where electrons and protons are randomly dispersed within an atom
Who concluded that most of the atoms mass was at the centre?
Ernest Rutherford
What is the gold foil experiment?
Alpha particles where shot at a thin piece of gold foil most travelled through but some bounced off.
Who showed that there was shells that housed electrons?
Neils Bohr
Who proved the existence of Neutrons?
James Chadwick
What is an Isotope?
The same atom but with different amounts of neutrons
What does the Atomic Number represent?
Number of protons in an atom
What does the mass number represent?
Number of protons and the number of neutrons.
How do you find out the relative mass percentage of isotopes?
(M x%)+(M x% )
100
How many electrons can the 1st shell hold?
2
How many electrons can the outer shell hold?
8
What must a shell be before a new one is started?
Full
Protons have what charge?
Positive
Electrons have what charge?
negative
Protons and Neutrons have a _________________
Protons and Neutrons have a relative mass of 1.
What does the pH scale measure?
Hydrogen ions
How many points are there on the pH scale?
14
What are the boundaries between strengths of acid and alkali?
1-3= strong acid
4-6=weak acid
7= neutral
8-10=weak alkali
11-14=strong alkali
Give 3 examples of common acids
-Hydrochloric acid (HCl)
-Sulphuric acid (H2 SO4)
-Nitric acid (HNO3)
-Ethanoic acid (CH3OOH)
Give 3 examples of common alkalis
-Sodium hydroxide (NaOH)
-Potassium hydroxide (KOH)
-Calcium hydroxide
(CaOH2)
-Magnesium hydroxide
(Mg(OH2)
Which is stronger, an acid or an alkali?
It depends on their pH
An acid has a high concentration of what ions?
Hydrogen (Positive)
An alkali has a high concentracion of what ions?
Hydroxide (Negative)
Hydrogen + oxygen
How would you test for hydrogen gas?
Trap the gas in a test or boiling tube and insert a lit splint and it will produce a squeaky pop.
What is the reactivity series?
The order is how quickly and violently something reacts.
Which group is the most reactive and give an example?
Group 1:
-K
-Na
-Li
What is it called when a metal “steals” the oxygen from another metal?
A displacement reaction
Acid + Alkali =?
Salt + Water
Give a definition for Calibrated
Set equipment to be correct
Give a definition for Accurate
Measuring the true value
Give a definition for Precise
Level of detail. Eg) decimal places
Give a definition for Reliable
Consistency in the results
Where do you read of the meniscus?
At the flattest line not the edges
How would you set up a Titration?
1)Rinse the burette with distilled water, then with the supplied acid. Fill the burette with the acid taking care to ensure that the bottom of the meniscus is on zero and that the jet of the burette is filled completely.
2)Rinse the pipette with distilled water, then with the alkali. Fill the pipette with the alkali, taking care with the pipette filler and ensuring that the bottom of the meniscus is on the ‘line’ of the pipette.
3)Carefully transfer the alkali in the pipette into a conical flask, to remove the final drop from the pipette, gently touch the end of the pipette onto the surface of the liquid in the conical flask.
4)Add 3 drops of phenolphthalein indicator to the conical flask and swirl gently to mix.
5)Place the conical flask onto a white tile underneath the burette.
6)Titrate the alkali with the acid, stop adding the acid when the indicator turns pink and remains pink.
What equipment would you need for a titration?
-Sodium hydroxide solution 100 cm3
0.1 mol/dm3 sulfuric acid, H2SO4 100 cm3
-Phenolphthalein indicator
-25.0 cm3 pipette and filler
-50.0 cm3 burette, retort stand and burette clamp
-Small funnel
-250 cm3 Conical flask (x3)
-Distilled Water
-White tile
What must acids and alkalis be dissolved in?
Water which makes the an aqueous
What is formed when an acid and a metal oxide are reacted?
Salt and water
What is formed when an acid and a metal carbonate are reacted?
Salt , water and carbon dioxide
