Periodicity + Bonding + Calculations

Question 1

Electrons are LEPTONS but which fundamental particles make up protons + neutrons?

Answer 1

Up and down quarks!

Question 2

Which electrons are used in forming bonds?

Answer 2

Electrons in the OUTERMOST subshell of electrons! (Valence electrons)

Question 3

P orbitals are shaped as…

Answer 3

3 - three dimensional hour glasses

Question 4

We can demonstrate that a mole contains 6.02x10^23 atoms or molecules because…

Answer 4

We can measure the charge on 1 mole of electrons

Question 5

Atomic radius…

Answer 5

DECREASES across a period - nuclear charge increases with NO new layers of electrons shielding.

Increases down group - new layers of electrons are shielding valence shells from nuclear charge!

Question 6

Ionic bond is strong because

Answer 6

Electrostatic Attraction between ALL ions in the lattice!

Question 7

A dative Covent bond is important in…

Answer 7

Keeping Iron in Haemoglobin

Question 8

Electronegativity AND Ionisation Energy…

Answer 8

Increases across a period - nuclear charge increased, NO additional shielding electrons so nuclear charge has GREATER influence over outer electrons!

DECREASES DOWN GROUP - new layers of shielding electrons DECREASE influence of nuclear charge on valence (outer shell) electrons!

Question 9

One mole of substance contains how many atoms or molecules?

Answer 9

6.02 x10^23

Question 10

One Mole of sodium would weigh how much?

Answer 10

23g - just it’s mass number!

Question 11

One mole of potassium chloride KCL would weigh how much?

Answer 11

• Find mass number (larger one) of K and all and then ADD them! *

39 + 35.5 = 74.5g

Question 12

To make a solution one mole/l how many moles would I add to 0.5l of solvent?

Answer 12

1 mole = 1 litre
so…

0.5 litre = 0.5 mole

Question 13

How much Calcium Carbonate CaCO3 would I need to add 0.1 litre of water to make a solution of 0.5 mole/l?

Answer 13

Find MR of CaCO3 first!

Ca = 40 / C = 12 / O = 16. Total= 100.

Moles = concentration x volume
0.5 x 0.1 = 0.05 moles.

Mass = moles x Mr
0.05 x 100 = 5g!!!

Question 14

C1 x V1 = C2 x V2.

If the volume of 0.3M potassium permanganate added was 500ml and the volume of water added was 500ml what was the FINAL CONCENTRATION of potassium permanganate?

Answer 14

C2 = C1 x V1 divided by V2.
TOTAL volume = 500 + 500 = 1000ml.

0.3 x 500 divided by 1000
= 0.15!

Question 15

How to convert ml to Ul?

Answer 15

Ml x1000 = ul

Question 16

How to convert L to ml?

Answer 16

L x1000 = ml

Question 17

If you ADD 100ul to 0.5M solution to 400ul water. What is the final concentration?

C(initial) x V(ADDED to tube) = C (final) x V(final)

Answer 17

0. 5 x 100 divided by 500 = 0.1M.
   * Don’t need to convert units as they are the same!
   * Remember total volume is 400 + 100!

Question 18

CONCENTRATION VALUES

Answer 18

1M = 1 mole per litre

1mM = 1 millimole per litre

1um = 1 micromole per litre!

Question 19

The subatomic particles found in atoms consist of which fundamental particles?

Answer 19

Quarks

Leptons

Question 20

What BEST describes an electron?

Answer 20

Electrons are leptons and found in a PAIRED state with one up and one down electron