Topic 2: Groups 1&7 Flashcards
What happens to the reactivity in group 1?
-The reactivity increases going down the group.
Observations of group 1 metals?
- Easier to cut going down the group.
- Turns universal indicator blue.
- The float so less dense then water.
- When cut they are shiny inside.
- All react with air.
- The sample of metal gets smaller.
Which gas you group 1 metal create when they react with water?
-Hydrogen.
Observations of sodium?
- Sodium more reactive then lithium.
- Turned into a ball-melted.
- Softer then lithium.
Observations of potassium?
- Lilac flame.
- Turned into a ball.
- Softest metal.
- More reactive then sodium.
What is the shielding effect?
-Electrons closer to the nucleus are more strongly attracted then those further away.
In group 1 why are the elements more reactive as you go down the group?
-In group 1 bigger atoms (more electrons) are more reactive.
What is a anion?
-A negatively charged ion (usual non-metal) one that gained electrons.
What is a cation?
-A positively charged ion (usually metal) one that has lost electrons.
Define Dissociation?
-The ability for ions to separate from each other, usually in solution.
Define Poler molecules?
-Molecules that have very strong inter-molecular forces of attraction, e.g. In water (if water is not poler).
Sulphuric acid?
-H2So4(l).
Sodium sulphate?
-Na2So4(aq)(aqueous in solution).
Sodium chloride?
-NaCl(s).
Hydrogen chloride?
-HCl(g).
What color do group 1 metals turn universal indicator paper, when mixed with water?
-Blue because it is forming a hydroxide OH-.
What is the shielding effect?
- Electrons closer to the nucleus are more strongly attracted then those further away.
- Inner electrons “shield” outer electrons from forces of attraction and from nucleus.
- In group 1 bigger atoms (more electrons) are more reactive.
What will happen when hydrogen chloride is dissolved in water?
- It will tern universal indicator paper red, however will not change it if it is dissolved in methyl benzene. use the idea of dissociation to explain this.
- Dissociation= the ability for ions to separate from each other, usually in solution.
Define Dissociation?
-The ability for ions to separate from each other, usually in solution.
Loss of electrons is called?
-Oxidation.
Gain in electrons is called?
-Reduction.
- What is oxidizing and what is reducing in this equation =
- 4Fe+3(O2)=2(Fe2)(O2)
- Fe=oxidation.
- O=reduction.
The way to remember oxidation and reduction?
-O I L R I G.
When a halogen is reduced(gains an electron)?
-It forms a halide.
Define Spectator ions?
-Ions that are neither oxidized nor reduced are called spectator ions.
What are transitions elements?
-These are (typical metals) They are hard, dense and shiny. they are good conductors of heat and electricity and are also malleable and ductile. They also have high melting points and boiling points, apart from mercury
Differences between Group one metals and transitions elements?
- Group 1 metals are soft while the transitions metals are very hard.
- Transitions metals are not very reactive, whilst group 1 metals are.
What is the difference between hydrogen chloride gas and hydrocloric acid?
-Hydrogen chloride gas has covelent bonds and also dissociates when dissolved in a polar solvent.
When are hailides formed?
-Formed when group 7 react with group 1 and visa verse.
Properties of group 7?
-Gas, gas, liquid, solid,solid. They are all different colors. They are also highly reactive.
How to check if hailade is formed?
-Take one hailide self dissolved in H2O add the other halogen solution. Observe the color changes.
Difference between hydrogen chloride gas and acid?
-When hydrogen chloride gas is dissolved in water the solution is hydrochloric acid. Hydrogen chloride is a covalent molecule.But, when it is dissolved in water, it forms H3O+ ion and Cl- ion.
When a more reactive halogen is added to a metal halide….
-The reactivity halogen will displace the less reactive halogen to form a new metal halide.
Experiments to show the displacement of the halogens?
-Reacting, chlorine and bromine water, iodine solution with potassium chloride, potassium bromide and potassium iodide.
Displacement reactions are…..
-Redox reactions.
Metals always…
-Metal atoms lose the electron, or electrons, in their highest energy level and become positively charged ions.
Non-metals always…
-Non-metal atoms gain an electron, or electrons, from another atom to become negatively charged ions
Explain the relative reactivity of the elements in Group 1 in terms of distance between the outer electrons and the nucleus?
-The more the electrons in group one the more reactive the element is.
Observations of Florine?
-Pale yellow gas, gas at room temperature.
Observations of chlorine?
-Pale green gas, gas at room temperature.
Observations of bromine
-Dark red liquid, readily gives off a brown vapor, solid at room temperature.
Observations of Iodine?
-Dark (~black) crumbly solid, purple vapor, solid at room temperature.
Observations of Astatine?
-Black solid, dark vapor – highly radioactive!, solid at room temperature.
-Properties of group 7?
-The boiling point increases gong down the group, colored elements. The group 7 elements react vigorously with group 1 elements such as sodium and potassium. In each case, a metal halide is formed (fluoride, chloride, bromide or iodide).
metal + water ->
Metal hydroxide + Hydrogen
Test for Hydrogen?
Squeaky pop form burning splint.
What happens when Hydrogen Chloride gas is bubbled into water, containing Universal indicator?
- starts Green.
- Turns red
- becomes acidic H+ ions formed.
Differences between the reaction of lithium and potassium reactions?
Similarity? Both release hydrogen. Both exothermic Differences? Potassium gives on lilac flame Potassium Melts into a ball.
Chemical equation between group 1 metal and water?
Metal + water -> metal hydroxide + hydrogen
Example of Group 1 reaction? Lithium
lithium + water → lithium hydroxide + hydrogen
2Li(s) + 2H2O(l) → 2LiOH(aq) + H2(g)
Chemical equation for ethanol?
CnH2n + OH
C2H5OH
Equation for conversion of ethanol to ethane?
C2H5OH -> C2H4 + H2O
State the name for the type of reaction that is done when converting ethanol to ethene?
Dehydration reaction
Catalyst used with dehydration reactions?
Aluminium oxide
Reactivity in Group 7 as you go down?
The reactivity of group 7 elements decreases down the group.
Group 7 why does the reactivity increase as you go down?
- The atoms get larger
- The outer shell gets further from the nucleus
- The attraction between the nucleus and electrons gets weaker, so an electron is less easily gained.
