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Chemistry > (1) Period 3 > Flashcards

(1) Period 3 Flashcards

1
Q

Outline the trend in Atomic Radius across Period 3.

A

DECREASES

  • Increase in Nuclear Charge
  • Same amount of Shielding
  • Increased attraction between positive nucleus and outer electrons
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2
Q

Outline the trend in Electronegativity across Period3.

A

INCREASES

  • Increase in Nuclear Charge
  • Same amount of Shielding
  • Electrons are increasingly able to withdraw electron density from a covalent bond
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3
Q

Outline the general trend in First Ionisation Energy across Period 3.

A

INCREASES

  • Increase in Nuclear Charge
  • Same amount of Shielding
  • Electrons are held increasingly tight to positive nucleus so require more energy to remove
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4
Q

Outline and Explain the 2 deviations from the general trend in First Ionisation Energy across Period 3.

A

Al has a lower 1st IE than Mg because:

  • Mg has a 3s electron removed
  • Al has a 3p electron removed
  • 3p is higher in energy than 3s

S has a lowest 1st IE than P because:

  • P has a 3p electron removed which is unpaired
  • S has a 3p electron removed which is paired
  • Paired electrons repel
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5
Q

Which does Melting Point increase from Na to Al?

A
  • Charge on the metal ion increases (Na+, Mg2+, Al3+)
  • Size of metal ion decreases across period
  • Increase in strength of attraction between the metal ions and delocalised electrons
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6
Q

Why does Silicon have the highest MP?

A
  • Macromolecular structure
  • Many covalent bonds
  • Which are very strong
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7
Q

Why does MP decrease from P4 to Ar?

A
  • P4, S8, Cl2 and Ar all have a simple molecular with Van der Waal’s between molecules
  • Strength of VdW’s depends on molecule’s size
  • S8 is largest, then P4, then Cl2, then Ar.
  • Ar exists as single atoms so has the weakest VdW’s between atoms.
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8
Q

Why does Al have the highest Boiling Point?

A

In the liquid state, Al still has strong electrostatic attractions between ions and delocalised electrons so still requires a large amount of energy to boil (whereas once Si has melted most of its strong covalent bonds have been broken so it requires only a little extra energy to boil).

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9
Q

Which of the Period 3 Oxides are Basic?

A

Na2O and MgO.

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10
Q

Which of the Period 3 Oxides are Acidic?

A

SiO2, P4O10 and SO2/SO3

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11
Q

Define Amphoteric.

A

Acidic or Basic.

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12
Q

Which of the Period 3 Oxides are Amphoteric?

A

Al2O3.

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13
Q

Which Period 3 Oxides are White Solids?

A

Na2O3, MgO, Al2O3 and SiO2.

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14
Q

Why do Na2O and MgO form an Alkaline Solution with Water?

A

-They contain O2- ions
-Which react with water
To form OH- ions

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15
Q

How does Al2O3 react with HCl?

A

Al2O3(s) + 6HCl(aq) –> 2AlCl3(aq) + 3H2O(I)

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16
Q

How does Al2O3 react with NaOH?

A

Al2O3(s) + NaOH(aq) + 3H2O(I) –> 2NaAl(OH)4(aq)

17
Q

Explain, using an equation, why Silicon Oxide is classified as an Acidic Oxide?

A

SiO2 neutralises bases.

SiO2 + 2NaOH –> Na2SiO3 + H2O

18
Q

Write an Ionic Equation for the reaction between Phosphorus Oxide and excess of Sodium Hydroxide.

A

P4O10 + 12OH- –> 4PO43- + 6H2O

19
Q

Which Period 3 Oxides are insoluble in Water?

A

Al2O3 and SiO2. When they are added to water, the pH is 7.

20
Q

How does Sodium react with Water? What pH is the solution formed?

A

2Na(s) + 2H2O(I) –> 2NaOH(aq) + H2(g)

pH = 13/14

21
Q

How does Magnesium react with Water? What pH is the solution formed?

A

Mg(s) + H2O(I) –> Mg(OH)2(aq) + H2(g)

pH = 9/10

22
Q

How does Magnesium react with Steam?

A

Mg(s) + H2O(g) –> MgO(s) + H2(g)

23
Q

How does Chlorine react with Water? What pH is the solution formed?

A

Cl2(g) + H2O(I) HClO(aq) + HCl(aq)

pH = 2/3

24
Q

How does Chlorine react with Water in the presence of sunlight? What pH is the solution formed?

A

2Cl2(g) + 2H2O(I) –> 4HCl(aq) + O2(g)

pH = 2/3

25
Q

What do the Na2O and MgO usually form when reacted with Water?

A

Alkaline Hydroxides.

26
Q

How does Na2O react with water? What is the pH of the solution formed?

A

Na2O (s) + H2O (l) –> 2Na+(aq) + 2OH-(aq)

pH = 13/14

27
Q

How does MgO react with water? What is the pH of the solution formed?

A

MgO(s) + H2O(l) –> Mg(OH)2(aq)

pH = 9/10

28
Q

How does P4O10 react with water? What is the pH of the solution formed?

A

P4O10 (s ) + 6 H2O (l) –> 4H3PO4(aq)

pH = 1/2

29
Q

How does SO2 react with water? What is the pH of the solution formed?

A

SO2(g) + H2O (l) –> H2SO3(aq)

pH = 2/3

30
Q

How does SO3 react with water? What is the pH of the solution formed?

A

SO3(g) + H2O(l) –> H2SO4(aq)

pH = 0/1

31
Q

What is the relationship between the bonding and acid/base properties of the Period 3 Oxides

A
  • Oxides which are IONICALLY bonded tend to be ALKALINE.

- Oxides which are COVALENTLY bonded tend to be ACIDIC.

Chemistry (29 decks)

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