Inorganic chemistry Flashcards
State 3 characteristics of Alkali metals
-One electron in their outer shell
-Low density
-Soft
How do Group 1 elements react with non-metals? why are these reactions similar for the different Group 1 elements?
They form ionic compounds which are soluble white solids which form colourless solutions-they all have one electron in their outer shell.
How do group 1 elements react with water
-Release H2 gas and form hydroxides
-Reactvigorously with water fizzing and moving around on the surface of the water.
How does reactivity change moving down Group 1? Why?
It increases as the electrons get larger and the distance between the nucleus and the outer shell electrons increases and thus attraction from the nucleus decreases, allowing them to more easily lose electrons
State 5 characteristics of elements in Group 7
-7 electrons in outer shell
-Coloured vapours
-Diatomic molecules
-Form ionic salts with metals
-Form molecular compunds with non metals
State 5 characteristics of Group 7
-7 electrons in outer shell
-Coloured vapours
-Diatomic molecules
-Form ionic salts with metals
-Form molecular compounds with non metals
State Group 7 gases and their states of matter.
Flourine→pale yellow gas
Chlorine→pale green gas
Bromine→Dark brown liquid
Iodine→Grey solid
Astatine→Solid
State 3 changes that occur in Group 7 as one moves down the group
-Higher relative melcular mass
-Higher boiling point
-Less reactive-electrons less easily gained
A more reactive halogen displaces a less reactive one from an aqueous solution of its salt; explain the trend in reactivity of halogens in these reactions
Reactivity decreases down the group. As we go down the group, the atoms get larger, so an incoming electron will be less tightly held by the attractive forces from the nucleus.
Solubility rules
Potassium, sodium and ammonium→SOLUBLE
Nitrate→SOLUBLE
Common Chlorides→SOLUBLE (exc. lead and silver).
Common sulfates→SOLUBLE (exc. lead, barium and calcium)
Common carbonates→INSOLUBLE (exc. sodium, potassium and ammonium).
Common hydroxides→ INSOLUBLE (exc. sodium, potassium and calcium).
Define rusting
Process of forming hydrated iron (III) oxide. Leaves a brown deposit on the surface of material
Outline how you would prepare a sample of PbSO4
Mix a soluble Pb (II) salt, with a source of sulfates. PbSO4 is insoluble in water-precipitate forms. Filter to collect the preciptate. Wash with H2O. Leave to dry
You have a sample of a pure liquid. How could you check its identity?
Measure its boiling point.
Outline how you would prepare a sample of NaCl from NaOH and HCl
In this case, we don’t know when to stop adding one of the reagents- there is no indication of the completion of out reaction. You can use an indicator in this case, just like in acid/base titration. Adding one of the reagents by a burette will help with accuracy. Then boi the mixture to remove some solvent and leave to crystallise. Filter and dry the product
How can you show that a liquid contains pure water?
Add the liquid being tested to a sample of pure, anhydrous crystals of CuSO4 (white). The positive test will result in the formation of the blue, hydrated copper (II) sulphate.
How could you test for the presence of NH4+ ions?
Add NaOH to the aqueous solution of the tested salt. Shake gently. Put a damp litmus paper near the outlet of the test tube. The damp litmus paper will turn blue of NH4+ were present in your solution (NH3 formation)
What is an oxidising and a reducing agent?
Oxidising: Gets reduced in a redox reaction (gains electrons; causes the oxidation of another substance).
Reduction: Gets oxidised in a redox reaction (loses electrons; causes the reduction of another substance).
What is the reactivity series? What are the trends in reactivities of metals in reaction with acids/water?
Metals above H2 in the reactivity series react with acids to produce H2. The more reactive the metal is, the quicker and more violent the reaction with acid is.
Metals below H2 don’t react with acids.
State the colours of flames observed when lithium, sodium and potassium burn in oxygen
Crimson-red. Li
Yellow-Orange. Na
Lilac. K
How to conduct a titration
1) Rinse a pipette with a solution of unknown concentration. Use the pipette to measure out the known volume of this solution
2) Add an indicator (Substance that changes the colour at the end of titration)
3) Rinse the burette with a solution of known concentration. Discard the liquid. Use a burette to gradually add the solution of known concentration
4) It is important to get concordant volue results-they have to lie close to each other
5) Suitable calculations are performed to find the concetration
