Review Questions 3 & 4

Question 1

Hydrogen has three isotopes, 1H, known as protium, 2H, deuterium, and 3H, tritium.

In terms of sub-atomic particles, give the similarities and differences between
atoms of these three isotopes of hydrogen [3]

Answer 1

• all have one proton
• all have one electron
• 1H has no neutrons, 2H has 1 neutron and 3H has 2 neutrons

Question 2

what is the mass number of an atom?

Answer 2

number of protons + number of neutrons

Question 3

When a nitrogen atom collides with a high energy neutron, one atom of tritium
and one atom of another element are formed.

Answer 3

ASK SERGEANT

Question 4

What is the RFM of molecules that each contain a deuterium and a tritium atom?

Answer 4

2 + 3 = 5 because the top number on deuterium is 2 and on tritium it is 3 so I’m guessing adding those gibes a mass numberish rfm

Question 5

Round 1.007950945 to FOUR decimal places

What happens after the point?

Answer 5

1.0080

4 numbers after the point I think

Question 6

Mark on the energy level diagram, with an arrow, the transition that
represents the ionization energy of hydrogen.

Answer 6

Arrow from N=1 all the way UPWARDS to n=infinity

Question 7

Which element in the periodic table has the highest ionisation energy?

Answer 7

• Helium
• Little shielding
• electron removed is closest to the nucleus
• Higher nuclear charge than hydrogen

Question 8

Explain why the lattice energy of calcium carbonate is less exothermic than that of magnesium carbonate. [2]

Answer 8

• Ca is a larger ion
• so has a weaker attraction (between its nucleus and the carbonate ion)

(so it is less exothermic because having a weaker attraction means when the bonds break less energy is released?? - this explanation cannot be right because bond breaking is endothermic - ASK SERGEANT

Question 9

When flame colour occurs, where are the electrons returning to?

Answer 9

Ground state

Question 10

Test and result for carbonate ions?

Answer 10

• add HCl

- carbon dioxide forms and turns limewater cloudy

Question 11

Calcium flame colour

Answer 11

orange/yellow-red

Question 12

Why does Mg2+ produce no flame colour?

Answer 12

emits light outside visible spectrum

Question 13

What state is barium carbonate?

Answer 13

solid

Question 14

2-chlorobutane reacts with silver nitrate in a mixture of ethanol and water as a solvent.
What would you see when the reaction occurred?

Answer 14

white precipitate (silver chloride I guess)

Question 15

Both ethanol and water contain hydrogen bonds.

By considering the hydrogen bonding on these two solvents, suggest why 2-chlorobutane is more soluble in ethanol than in water. [2]

Answer 15

• Water has more hydrogen bonds per molecules than ethanol

- Which would require more energy to break

Question 16

What would be the main difference between the infrared spectrum of a carboxylic acid compared to a ketone?

Answer 16

there would be a peak for the O-H absorption in the carboxylic acid spectrum but not in the ketone spectrum