Chem Notes

What is MASH

metal + acid --\> salt + hydrogen

What is RAM

Average mass of isotopes of an element

What is Mr

The RA, of all of the atoms in that compund molecular formula

What does litmus turn into in acid?

red

What does litmus turn into in alkaline?

blue

What does litmus turn into in neutral solutions?

purple

What does methyl orange turn into in acid?

red

What does methyl orange turn into in alkaline?

yellow

What does methyl orange turn into in neutral solutions?

yellow

What does phelonthalien turn into in neutral solutions?

colourless

What does phenolthalien turn into in acid?

colourless

What does phelonthalien turn into in alkaline?

pink

What is an aqueous neutralization?

Hydroxide ions + hydrogen ions \> water

What ions do transition metals form?

+2

How do you form the name of the salt in a neutralization reaction?

First part \> base

Second part \> acid

metal oxide + acid \>

salt + water

carbonate + acid \>

salt + water (H2O) + carbon dioxide (CO2)

Group 1 metals have an ion of ?

+1

Group 2 metals have an ion of ?

+2

How is how weak or strong an acid is decided?

How much they ionize in solutions

Strong - fully ionise

weak - don't fully ionise

What is an example of a weak and strong acid?

Weak

- Ethanoic Acid

Strong

Hydrochloric acid

What are groups on the periodic table?

vertical columns

What are periods on the periodic table?

horizontal rows

How do you find the group of an element of the periodic table?

Look for the number of electron in the outershell

How do you find the period of an element in the periodic table?

The number of shells the element

What is the order in which the metals reacts from highly reactive to non-reactive ?

- Potassium

- Sodium

- Calcium

- Magnesium

- Aluminium

- Zinc

- Iron

- Copper

- Silver

- Gold

How does magnesium, aluminum, zinc and iron react with water?

Reacts very slowly, if at all w/ cold water.

- But reacts with stream -\> hydrogen & metal oxide

How does potassium, sodium and calcium react with water?

- Reacts with cold water to form hydrogen & metal oxide

How does copper, silver and gold react with water?

- Do not react with cold water or stream

How does magnesium, aluminum, zinc and iron react with dilute acid?

- Reacts to form hydrogen & a salt solution

How does potassium, sodium and calcium react with dilute acid?

- Reacts very violently

How does copper, silver and gold react with dilute acid?

- they do not react

What is the order of increasing ability for some metal atoms to form positive ions?

- Gold

- Silver

- Copper

- Iron

- Zinc

- Aluminium

- Magnesium

- Calcium

- Sodium

- Potassium

What is a displacement reaction?

A reaction in which a more reactive element takes the place of a less reactive element in a compound

What is a Hofmann Voltameter?

The Hofmann Voltameter is an apparatus for electrolysing water

How do you calculate number of mols when using no of particles and an Avagadro's No

No of particles / Na (Avogadro's number)

How do you calculate the no of particle in an element using mols?

- Avogadro's number x mols

What is the difference between an empirical formula and molecular formula?

- Empirical Formular is the simplest whole number ratio of atom of an element in a compound.

- Molecular formula is the sum of the RAM of all the the atoms in the compound

The steps in determining the empirical formula for magnesium oxide?

- Find the mass of a crucible

- Clean the magnesium ribbon with emery paper

- Coil the magnesium ribbon so that it fits in the crucible. Find the mass of the crucible, lid and magnesium ribbon

- Set up the apparatus as shown in the diagram

- Heat crucible strongly. Occasionally lift the lid with a pair of tongs. Continue heating until all of the magnesium has has completely

- Allow the crucible to cool to room temp

- Find the mass of the crucible, lid and magnesium oxide

- Record your results in a suitable

- Calculate the empirical formula for magnesium oxide

- State why it was necessary to lift the lid if the crucible occasionally during heating

- Describe how you knew when all of the magnesium had completely burned

Why is it necessary to lift the lid of the crucible occasionally during heating?

- To allow the oxygen to get into the crucible and react with magnesium ribbon

What is allotropes ?

A different structural form of an element

What is an anion?

A negatively charged ion formed by gaining electrons

What is a cation?

A positively charged ion formed by losing electron

What is a fullerene?

Molecule in which a carbon atom is covalently bonded to three other carbon atom

Describe in terms of electrons, how magnesium atoms and chlorine atoms change into ions to produce magnesium chloride?

A magnesium atom tries to lose 2 electrons and a chlorine atom tries to gain one electron. So the magnesium atoms give one electron to a chlorine atom making that atom have a full outer shell and then give that other electron to another chlorine atom making that one also have a full. Since the magnesium atom has now lost 2 electron, it also has a full outer shell making hem all ions.

Why is Argon reactive?

It is in group 8/group 0 on the periodic table and has a complete outer shell of electrons

Why is oxygen not a suitable gas to use in a light bulb?

It is reactive and therefore will react with the filament in the light bulb

Give one use of chlorine

Water treatment: chlorine is used to purify water and in swimming baths, to prevent life-threatening diseases. The benefits to health of water treatment by chlorine outweigh its toxic effects.

What is the reactivity series?

A list of elements ordered by their reactivity

What is the reactivity order for group 7?

The reactivity for the element decreases as you go down the group.

Florine is the most reactive and astatine is the least reactive

Why does reactivity decrease going down group seven?

- The atomic mass of the halogens increase

\-- They increase in electron shells; so the atoms are larger as you go down the group. Therefore, the attraction of the outer electron to the nucleus decreases as you go down group 7.

- The number of electrons increase.

\-- There are more electrons shielding the positively charged nucleus from the outer electron. Therefore, the attraction of the outer electron to the nucleus decreases as you go down group 7.

What is the reactivity order for group 1?

The reactivity for the element increases as you go down the group.

Lithium is the least reactive and Francium is the most reactive

Why does reactivity increase as you go down group 1?

- The atoms get larger an the outer electron get further from the nucleus

\-- The attraction between the nucleus and the outer electron gets weaker - so the electron is more easily lost

What is the trend in the melting and boiling points in group 1?

Both the melting and boiling points decrease going down the group?

Why does the melting and boiling point decrease as you go down the elements in group 1?

Because the there is a decrease in the strength of each metallic bond

What colour flame does lithium produce when set on fire?

red