Chapter 8 Reactivity Trends Flashcards by Thomas Gorby

What sub-shell are the outer electrons of group 2 elements in

How well did you know this?

Not at all

Perfectly

What is the reaction of calcium becoming an ion

Ca → Ca²⁺ + 2e^-

How well did you know this?

Not at all

Perfectly

Why are group 2 elements called reducing agents

Group 2 element are called reducing agents because they have reduced another species. Group 2 elements are oxidised to produce 2+ ions

How well did you know this?

Not at all

Perfectly

What do group 2 elements produce when they react with oxygen and what is the formula

Metal oxide
MO

How well did you know this?

Not at all

Perfectly

What is the equation of Magnesium reacting with Oxygen

Mg_(s) + ½O_2(g) → MgO_(s)

How well did you know this?

Not at all

Perfectly

What are the half equations for the reaction and the Oxidation numbers:
Mg_(s) + ½O_2(g) → MgO_(s)

Mg → Mg²⁺ + 2e^-
0 → +2
Mg Oxidised

½O₂ + 2e^- → O_2-
0 → -2 Reduced

How well did you know this?

Not at all

Perfectly

What do group 2 metals react with water to produce and what is the formula

An alkaline hydroxide + Hydrogen Gas
M(OH)₂

How well did you know this?

Not at all

Perfectly

What are the observations of Group 2 elements reacting with water

Bubbling
Solid disappears

How well did you know this?

Not at all

Perfectly

Does reactivity increase or decrease down group 2

Increases

How well did you know this?

Not at all

Perfectly

What is the equation for the reaction of Strontium with Water

Sr_(s) + 2H₂O_(l) → Sr(OH)_2(aq) + H_2(g)

How well did you know this?

Not at all

Perfectly

In the reaction
Sr_(s) + 2H₂O_(l) → Sr(OH)_2(aq) + H_2(g)
What has been oxidised and what has been reduced

Strontium Oxidised
Hydrogen Reduced

How well did you know this?

Not at all

Perfectly

Group 2 Element + Dilute Acid →

Salt + Hydrogen
MASH

How well did you know this?

Not at all

Perfectly

What is the equation for the reaction of Magnesium with Hydrochloric Acid

Mg_(s) + 2HCl_(aq) → MgCl_2(aq) + H_2(g)

How well did you know this?

Not at all

Perfectly

In the equation of Mg With HCl
Mg_(s) + 2HCl_(aq) → MgCl_2(aq) + H_2(g)
What is oxidised and what is reduced

Mg Oxidised
H Reduced

How well did you know this?

Not at all

Perfectly

How many ionisation energies does the formation of a 2+ ion involve

How well did you know this?

Not at all

Perfectly

What is the equation of the first ionisation energy of a group 2 element M

M_(g) → M⁺_(g) + e^-

How well did you know this?

Not at all

Perfectly

What is the equation of the second ionisation energy of a group 2 element M

M⁺_(g) → M²⁺_(g) + e^-

How well did you know this?

Not at all

Perfectly

Why do the ionisation energies decrease down a group

Atomic Radius Increases
Inner Shell Shielding increases
Nuclear Attraction decreases

How well did you know this?

Not at all

Perfectly

Going down group 2, does the reducing ability increase or decrease

Increases

How well did you know this?

Not at all

Perfectly

What is produced when group 2 Oxides react with water

hydroxide ions
alkaline solutions of the metal hydroxide

How well did you know this?

Not at all

Perfectly

What is the equation of Calcium oxide with Water

CaO_(s) + H₂O_(l) → Ca²⁺_(aq) + 2OH^-_(aq)

How well did you know this?

Not at all

Perfectly

How soluble are Group 2 Hydroxides in water

The Group 2 hydroxides are only slightly soluble in water

How well did you know this?

Not at all

Perfectly

What happens when a solution of water and group 2 hydroxides becomes saturated

Any further metal and hydroxide ions will form a white precipitate

How well did you know this?

Not at all

Perfectly

As you go down the group 2 hydroxides, do Solubility, Alkalinity and PH increase or decrease

Going down group 7
* solubility increases
* pH increases
* alkalinity increases
As solubility increases, the resulting solutions contain more OH-(aq) ions and are more alkaline

How well did you know this?

Not at all

Perfectly

How is Calcium Hydroxide Ca(OH)₂(a base) used in agriculture

is added to fields as lime by farmers to increase the pH of acidic soils in a neutralisation reaction Ca(OH)_2(s) + 2H⁺_(aq) → Ca²⁺_(aq) + 2H₂O_(l)

How are group 2 Bases used in medicine

Group 2 bases are often used as antacids for treating acid indigestion Mg(OH)2(s) + 2HCl(aq) → MgCl2(aq) + 2H2O(l) Magnesium and calcium carbonates are the main ingredients in indigestion tablets

Are group 7 elements oxidising agents or reducing agents

oxidising agents

What sub shells are the outer 7 electrons of group 7 elements in

2 are in the outer s sub-shell and 5 are in the outer p sub-shell

What colour is chlorine solution in water

Pale Green

What colour is Bromine solution in water I2(aq)

Orange

What colour is Iodine solution in water I2(aq)

Brown

What colour is Chlorine in a non-polar solvent

Pale Green

What colour is Bromine in a non-polar solvent

Orange

What colour is Iodine in a non-polar solvent

Purple

What state and colour is Fluorine in at RTP

Pale Yellow Gas

What state and colour is Chlorine at RTP

Pale Green Gas

What state and colour is Bromine at RTP

Red-Brown Liquid

What state and colour is Iodine at RTP

Shiny Grey - Black Solid

What state and colour is Astatine at RTP

Never been seen

Does the boiling point increase or decrease down the group 7

Increases

Why does the boiling point increase going down group 7

* More electrons * Stronger London Forces * More energy required to break the intermolecular forces * Boiling Point increases

Does reactivity increase or decrease down group 7

Decreases down the group

Why does reactiity decrease down group 7

* Atomic Radius increases * More inner shell shielding * Less attraction to gain an element * Reactivity decreases

Does oxidising ability increase or decrease down the group

Decreases

What is Disproportionation

A redox reaction in which the same element is both oxidised and reduced

What is the equation for the reaction of chlorine with water

Cl2(aq) + H2O(l) → HClO(aq) + HCl(aq)

What is the reaction of chlorine with cold dilute aqueous sodium hydroxide

Cl2(aq) + 2NaOH(aq) → NaClO(aq) + NaCl(aq) + H2O(l)

What is the benefit of chlorine use

Chlorine is beneficial in ensuring our water is safe to drink, by killing all bacteria present

What are the risks of Chlorine Use

Chlorine is an extremely TOXIC gas: * in small concentrations it is a respiratory irritant. * in large concentrations it can be fatal. Chlorine added to drinking water can react with organic hydrocarbons, such as methane, to form chlorinated hydrocarbons – a suspected carcinogen

Cl2(aq) + 2Br-(aq) →

2Cl-(aq) + Br2(aq)

Cl2(aq) + 2I-(aq) →

2Cl-(aq) + I2(aq)

Br2(aq) + 2I-(aq) →

2Br-(aq) + I2(aq)

How do you test for halide ions

Add aqueous silver ions to aqueous halide ions to form a precipitate of silver halide

What is the ionic equation for testing for Halide ions

Ag+(aq) + X-(aq) → AgX(s)

What colour is the precipitate formed when testing for Chloride ions Is it soluble in Dilute NH3 or Concentrated NH3 or not at all

White Soluble in dilute NH3

What colour is the precipitate formed when testing for Bromide ions Is it soluble in Dilute NH3 or Concentrated NH3 or not at all

Cream Precipitate Soluble in concentrated NH3

What colour is the precipitate formed when testing for Iodide ions Is it soluble in Dilute NH3 or Concentrated NH3 or not at all

Yellow Precipitate Insoluble in concentrated NH3

How do you test for Carbonates

Add dilute nitric acid to a test tube containing the unknown compound Observation - Bubbles of gas

What is the ionic equation for a Carbonate test

CO32-(aq) + 2H+ → CO2(g) + H2O(l)

How do you test for sulfates

Add barium nitrate to a test tube containing a solution of the unknown compound Observation – a white precipitate (of barium sulfate) forms

What is the ionic equation for the sulfate test

Ba2+(aq) + SO42-(aq) → BaSO4(s)

What is the order you should perform the anions tests in

1. Carbonate, CO32- 2. Sulfate, SO42- 3. Halides, Cl-, Br-, I-

Why do you do the anion tests in this order: 1. Carbonate, CO32- 2. Sulfate, SO42- 3. Halides, Cl-, Br-, I-

* If carbonate ions are present when testing for sulfate ions (addition of barium nitrate) – a white precipitate of barium carbonate, BaCO3(s), will form. * If carbonate ions and/or sulfate ions are present when testing for halide ions (addition of silver nitrate) – white precipitates of silver carbonate, Ag2CO3(s), and/or silver sulfate, Ag2SO4(s) will form.