Electromagnetic Radiation And Atomic Spectra

Question 1

How many meters are in 1nm?

Answer 1

10^-9m

Question 2

What is a photon?

Answer 2

Particles with a fixed quantity of EM radiation

Question 3

What is a dative covalent bond?

Answer 3

Both electrons in the covalent bond are donated by one of the atoms.

Question 4

Describe why many transition metals complexes are coloured.

Answer 4

Absorption of visible light causes electrons to move from low energy d orbitals to higher energy d orbitals. The TM complex colour is the complementary colour of the colour that has been absorbed.

Question 5

What is an indicator?

Answer 5

A weak acid that has a colour gor the weak acid and a different colour for conjugate base used in acid-base titrations.

Question 6

Indicator for pH of equilibrium point 7

Answer 6

Bromothymol blue

Question 7

// for pH 5

Answer 7

Methyl red

Question 8

// pH 9

Answer 8

Phenolpthalein

Question 9

Choosing an indicator for a weak/weak titration

Answer 9

Too gradual to detect, N/A

Question 10

When is the colour change of an indicator assumed to be distinguishable?

Answer 10

When these differ by a factor of 10.

Question 11

What is the units of k when the order of the reaction is 0

Answer 11

Mol l-1 s-1

Question 12

What is the units of k when the order of the reaction is 1

Answer 12

S-1

Question 13

What is the units of k when the order of the reaction is 2

Answer 13

L mol-1 s-1

Question 14

What is the units of k when the order of the reaction is 3

Answer 14

L2 mol-2 s-1

Question 15

What is meant by „accurately weigh approximately“?

Answer 15

The accurate mass must be recorded but it does not need to be the exact amount.

Question 16

How is the filter in colorimetry chosen?

Answer 16

Filter is the complementary colour to the colour of solution.

Question 17

How would you prepare a series of standard solutions to be used in colorimetry?

Answer 17

Use a standard stock solution and accurately measure the required volume into a standard flask. Make to mark with solvent (usually distilled water). Repeat to make series of dilutions.