Alkali Metals 2 Flashcards
<p>Group 1 of the Periodic Table contains ..........</p>
<p>Lithium (Li)</p>
<p>Sodium (Na)</p>
<p>Potassium (K)</p>
<p>Rubidium (Rb)</p>
<p>Caesium (Cs)</p>
<p>Why do you think that the Group 1 metals are stored under oil?</p>
<p>A) To keep them moist and ready to react in experiments</p>
<p>B) To keep them out of contact with oxygen in the air</p>
<p>C) To lubricate the surface of the metal</p>
<p><strong>B</strong></p>
<p></p>
<p>The table below shows that Group 1 elements have low melting points for metals:<br></br><br></br></p>
<p>Group 1 metalMelting point (°C)</p>
<p>Lithium 180</p>
<p>Sodium 98</p>
<p>Potassium 63</p>
<p>Rubidium 39</p>
<p></p>
<p>Look at the table above. Which statement below is true?</p>
<p>A) There is no pattern in the melting points of the Group 1 metals as we go down the group.</p>
<p>B) The melting points of the Group 1 metals decrease as we go down the group.</p>
<p>C) The melting points of the Group 1 metals increase as we go down the group.</p>
<p><strong>B</strong></p>
<p>Predict the approximate melting point of caesium, theelementbelow rubidium in Group 1.</p>
<p>Between 40 °C and 50 °C</p>
<p>Between 20 °C and 30 °C</p>
<p>Between 60 °C and 70 °C</p>
<p>B</p>
<p>Which Group 1 metal is most difficult to cut with a knife and has the highest melting point?</p>
<p>Sodium</p>
<p>Lithium</p>
<p>Potassium</p>
<p>Rubidium</p>
<p>Caesium</p>
<p>Lithium</p>
<p>Liquid sodium is piped around some nuclear power stations to transfer heat. Which two properties of sodium make it suitable for this use?</p>
<p>It has a low melting point.</p>
<p>It is a good conductor of heat.</p>
<p>Group 1 metals are called thealkali metals. why?</p>
<p>They get their name from their reaction with water, which produces an alkaline solution</p>
<p>Which of the alkali metals shown below melts into a silver ball that moves around the surface of the water as it reacts?</p>
<p>Potassium</p>
<p>Sodium</p>
<p>Lithium</p>
<p>Sodium</p>
<p>You can collect the gas given off as lithium reacts with water. Which test shows that the gas collected is hydrogen?</p>
<p>A glowing splint re-lights</p>
<p>A lighted splint explodes with a squeaky 'pop'</p>
<p>Limewater turns milky</p>
<p>A lighted splint explodes with a squeaky 'pop'</p>
<p>What is thepH valueof the solution produced when the Group 1 metals react with water?</p>
<p>7</p>
<p>Greater than 7</p>
<p>Less than 7</p>
<p>Greater than 7</p>
<p>Which of the three metals is most reactive with water?</p>
<p>Lithium</p>
<p>Potassium</p>
<p>Sodium</p>
<p>Potassium</p>
<p>Caesium explodes when put into water, smashing the glass trough. Which statement do you think describes the pattern in reactivity as we go down Group 1?</p>
<p>The Group 1 metals get less reactive as we go down the group.</p>
<p>The Group 1 metals get more reactive as we go down the group.</p>
<p>There is no pattern in their reactivity.</p>
<p>The Group 1 metals get more reactive as we go down the group.</p>
<p>What is the equations ofthe reaction between rubidium and water?</p>
<p></p>
<p>2 Rb(s)+2 H2O(l)2 RbOH(aq)+H2(g)</p>
<p>What is the equation of the reaction lithiumand water?</p>
<p>lithium+waterlithium hydroxide+hydrogen<br></br>2 Li(s)+2 H2O(l)2 LiOH(aq)+H2(g)</p>
<p>What is the equation of the reaction sodium and water?</p>
<p>sodium+watersodium hydroxide+hydrogen<br></br>2 Na(s)+2 H2O(l)2 NaOH(aq)+H2(g)</p>
<p>What is the equation of the reaction potassiumand water?</p>
<p><br></br>potassium+waterpotassium hydroxide+hydrogen<br></br>2 K(s)+2 H2O(l)2 KOH(aq)+H2(g)</p>
<p>Which of the equations below show possible reactions of lithium?</p>
<p>A) 4 Li(s)+O2(g)2 Li2O(s)</p>
<p>B) Li(s)+Cl2(g)2 LiCl2(s)</p>
<p>C) 2 Li(s)+Cl2(g)2 LiCl(s) </p>
<p>D) Li(s)+O2(g)LiO2(s)</p>
<p>A & C</p>
<p>Write the equation showing the formation of potassium oxide is:<br></br><br></br></p>
<p>potassium+oxygenpotassium oxide<br></br>4 K(s)+O2(g)2 K2O(s)</p>
<p>The alkali metals react vigorously when heated with chlorine gas. Give an example:<br></br><br></br></p>
<p>sodium+chlorinesodium chloride<br></br>2 Na(s)+Cl2(g)2 NaCl(s)</p>
<p></p>
<p>potassium+chlorinepotassium chloride<br></br>2 K(s)+Cl2(g)2 KCl(s)</p>
<p>Summary</p>
<p>Group 1 elements are called the alkali metals.<br></br><br></br>They are soft metals that tarnish quickly in air.<br></br><br></br>The Group 1 metals get more reactive as we go down the group.<br></br><br></br>Their melting points decrease as we go down the group. The melting points are all low for metals, as are the densities of these elements.<br></br><br></br>The alkali metals are the most reactive group of metals in the Periodic Table. They form soluble compounds that are usually white.<br></br><br></br>They react vigorously with water, giving off hydrogen gas and producing an alkaline solution.<br></br><br></br>Because they are very reactive, they are stored under oil.</p>
<p>Name the product of the reaction between potassium and chlorine.</p>
<p>Potassium chloride</p>
<p>Potassium oxide</p>
<p>Potassium chlorate</p>
<p></p>
<p>Potassium chloride</p>
<p>Predict the colour of the product in the previous question.</p>
<p>White</p>
<p>Caesium+water…</p>
<p></p>
<p>caesium hydroxide+hydrogen</p>
<p>As theatomic numberof an alkali metal increases, its reactivity …</p>
<p>increases</p>
Which gas is given off when an alkali metal reacts with water?
hydrogen
Which of these alkali metals is easiest to cut with a knife?
Lithium
Sodium
Potassium
Potassium
Which of the alkali metals has the highest melting point?
Lithium
Sodium
Potassium
Rubidium
Caesium
Lithium
what is the electronic structure for the below atoms
Sodium
Potassium
Lithium
Sodium 2,8,1
Potassium 2,8,8,1
Lithium 2,1
How many electrons are in the highest energy level (outer shell) of all the Group 1 metals?
1
What is the charge on the ion formed when an atom of an alkali metal reacts?
+1
Which of these would make it easier for an atom to lose an electron?
The electron being nearer to the positively charged nucleus
The electron being further from the positively charged nucleus
The electron being further from the positively charged nucleus
Why do the alkali metals get more reactive as we go down the group?
Because
This is because as we go down the group the outer electron of the atom is further from the attractive force of the nucleus. It is also shielded from the nucleus by more complete lower energy levels (full inner shells) of electrons.
If an electron is further from the attractive force of the nucleus, it is easier to remove it from the atom so it becomes more reactive
Why the alkali metals are the most reactive group of metals in the Periodic Table?
the atoms of alkali metals all have just one electron in their highest energy level (outer shell) and It is relatively easy to lose this one electron
losing this outer electron, they form stable ions with a 1+ charge, e.g. Na+.
As we go down Group 1,
The outer electron is more tightly held by the nucleus in larger atoms. True/False
The outer electron is further from the attractive force of the nucleus in larger atoms.
True/False
The outer electron is shielded from the attractive force of the nucleus by more inner shells of electrons. True/False
The outer electron in larger atoms is more strongly attracted by neighbouring atoms.
True/False
The outer electron is more tightly held by the nucleus in larger atoms. False
The outer electron is further from the attractive force of the nucleus in larger atoms.
True
The outer electron is shielded from the attractive force of the nucleus by more inner shells of electrons. True
The outer electron in larger atoms is more strongly attracted by neighbouring atoms.
False
Are these statements true or false?
•Metals are on the right of the periodic table.
•Metal hydroxide is made when metals react with air.
•Group 1 metals are kept under oil.
•Hydrogen is produced when group 1 metals react with water.
•Hydrogen is tested with limewater.
•Lithium is the most reactive group 1 metal.
•Metals are on the right of the periodic table. (F)
•Metal hydroxide is made when metals react with air. (F)
•Group 1 metals are kept under oil. (T)
•Hydrogen is produced when group 1 metals react with water. (T)
•Hydrogen is tested with limewater. (F)
•Lithium is the most reactive group 1 metal. (F)
•Name two group 1 metals
•Describe the trend in reactivity down period 1
•Explain the trend in reactivity down group 1
•Explain why group 1 metals are called the alkali metals
•What gas is produced when the group 1 metals react with water- how can we test for the presence of this gas?
•Name two group 1 metals
Lithium and sodium
•Describe the trend in reactivity down period 1
they get more reactive as we go down the group and the reactions occur more rapidly
•Explain the trend in reactivity down group 1
As we move down the group the atoms have more shells of electrons and the atom gets bigger. and as the atom gets bigger the outer electrome is further from the nucleus so it is less strongly attached by the nucleus , and therefore it is more easily lost.
•Explain why group 1 metals are called the alkali metals
Because they react with water forming a metal hydroxide which is alkaline. PH above 7 (universal indicator is blue) (OH- ion)
•What gas is produced when the group 1 metals react with water- how can we test for the presence of this gas?
Hydrogen which burns with a lilac flame.
Alkali metals react with oxygen to form
metal oxides
Alkali metals react with halogens to form
IONIC SALTS
The alkali metals react with water to form
METAL HYDROXIDES
The melting and the boiling point of halogens become ................... as we go down the group, and the molecules become ...........
increase, bigger
Why Lithium, Sodium and Pottasium float on water?
Becasue they are less dense than water
Chemical properties of group 1
- they all react with water in the same way to form a hydroxide with the formula MOH
- they all react with oxygen to form oxide with the formula M2O
- they all react with halogens to form compunds with the formula MX
- they form ionic compunds which contain an M+ ion.
Physical properties of group 1
Li/Na/K/Rb/Cs/Fr
as we go down the group the
meting point ( increases/ decreases)
boiling point ( increases / decreases)
denisty g/cm3 ( increases/ decreases)
softness (increases / decreases)
meting point ( increases/ decreases)
boiling point ( increases / decreases)
denisty g/cm3 ( increases/ decreases)
Physical properties of elements in group 1
- melting points are very low
- densities is low
- very soft and easily cut with knife
- shiny and silver whne freshly cut but tarnish very quickly on exposure to air.
chemical properties depend on............
chemical properties of group 1 elements as we go down the group
the number of electrones in the outer shell
more reactive with water
more reactive with air tarnishes quickly
more reactive with halogens
Write the equation of sodium reaction with water with state symbol
2Na(s) + 2H2O(l) --> 2NAOH(aq) + H2(g)
Sodium is usually used ad molten sodium but to avoid confusion we write state symbol as (s)
what is your observation for the sodium water reaction?
- the sodium floats because it is less dense than water
- the sodium melts into a ball because its melting point is low and a lot of heat is produced by the reaction (exothermic)
- there is fizzing because hydrogen gas is produced.
- the sodium moves around on the surface of the water because the hydrogen isn't given off symmetrically around the ball, the sodium is pushed around the surface of the water by the hydrogen.
- the piece of sodium gets smaller an eventually disappears ( used up)
- test using universal indicator gives blue.
lithium reaction with water compared to sodium reaction with water
It is very similar except that it is (slower / faster)
lithium ( melts/ doesn't melt)?
It is very similar except that it is slower
lithium ( melts/ doesn't melt)
when lithium reacts with water it doesn't melt. explain why?
because the melting point of lithium is higher and the heat isn't produced so quickly so the lithium doesn't melt.
lithium reaction with water is slower than sodium reaction with water
how can you observe this in the experiment?
lithium reaction
fizzes more slowly
lithium moves around the surface of water more slowly.
lithium takes longer to disappear.
compare potasium reaction with water and sodium reactions with water
Potassium
fizzes more vigorously
moves around more quickly
disappears more quickly
disappears more quickly
Key difference : with potassium the hydrogen bursts into flame but in sodium does not
- compare rabidium and caesium reaction with water and sodium reaciton with water
- what is your predection about francium?
rabidium and caesium reaction can be explosive.
Francium is even more explosive
VERY IMPORTANT
write the water half equation when group 1 metal reacts with water. producing a hydroxide.
write the half equation when group1 metal reacts with water forming metal ions in solution ( example sodium)
2H2O(l) + 2e- ---> 2OH-(aq) + H2(g)
Na(s) ---> Na+(aq) + e-
burning group 1 metals in the qir we get vigorous reaction , state the different flame colours of burning
lithium
sodium
potassium
lithium : red flame to form lithium oxide
sodium : yellow flame to form sodium oxide
potassium : lilac flame to form potassium oxide
when burning lithium , sodium and pottasium
what is the desctiption of the product formed?
what is the equation?
what other types of oxides can be formed?
It is a white powder in solid state, it is the alkali metal oxide.
they all have the same equation
4M(s) + O2(g) ----> 2M2O(S)
other types of oxides
peroxides (M2O2)
and superoxides (MO2)
lithium can also form a nitride (Li3N)
Explain why lithium , sodium and potassium are put in the same group in the periodic table?
VERY IMPORTANT
They all have one electrone in their outer shell . the elctronic configurations are:
lithium : 2,1
Sodium, 2,8,1
Potassium 2,8,8,1
also they have similar chemical properties such as
- they react with water in the same way to form hydroxide with the formula MOH
- they react with oxygen to form oxide with the formula M2O
- they react with halogens to form compunds with formula MX
- they form ionic compunds which contain an M+ ion.
summary of groups 1 main features
- are metals
- are soft with melting point and densities which are very low for metal.
- have to be stored out of contact with air or water
- react rapidly with air to form coatings of the metal oxide
- react with water to produce alkaline solution of the metal hydroxide and hydrogen gas
- increase in reactivity as you do down the group
- form compunds in which the metal has a 1+ ion
- have mainly white colourless coumpunds which dissolve to produce colourless solutions.
find the names of the below letters
B is a metal when dropped onto water it melts into a small ball and moves rapidly around the surface , a gas C is given off and this burns with a lilac flame a solution D is formed
write the reaction equation with state symbol
B = Potassium
C = hydrogen
D = Potassium hydroxide KOH
2K(s) + 2H2O(l) ---> 2KOH(aq) + H2(g)
Explain why all metals in group 1 they react the same with water?
chemical properties depend on the number of electrons in the outer shell, and since they all have the same number of electrone in the outer shell (one) so they all have similar chemical properties and react the same with water.
All metals in group 1 they react the same way with water
write the equation
write the equation for fracium
2M + 2H2O ----> 2MOH + H2
2Fr(s) + 2H2O(l) ----> 2FrOH(aq) + H2(g)
predict the features of facium (Fr)
very soft
melting point is around the room temperature
has density over 2g/CM3
silvery metal tarnish instantly when cut
react with water violently forming fracium hydroxide and hydrogen
the solution FrOH is strongly alkaline
will form compounds that are white / clourless and dissolve in water giving a colourless solution.
Congratulations you discovered a new alkali metal named Ed
is it more or less dense than fracium?
is the melting point higher or lower than fracium?
how many electrons does it have?
what is the equation to react with water?
is the solution acidic or akaline?
what is the equation to react with oxygen?
what is the equation to react with Cl
is it more or less reactive than fracium?
GUESS
