Arsenic

Question 1

What is the most common poison used, especially in Roman times ?

Answer 1

White arsenic

As2O3

Question 2

What kind of metal is arsenic?

Answer 2

Semi-metal or metaloid

Question 3

What are the 2 forms of arsenic?

Answer 3

As(III) and As(V)

Question 4

Which As is more toxic?

Answer 4

As(III) because it can be retained longer

Question 5

What are the main anthropogenic sources of As?

Answer 5

Pesticides
Released during mining
Combustion of coal
Iron and steel production

Question 6

What is the main way of extraction As?

Answer 6

1. Mining
2. Combustion of coal
   - depending on where the coal comes from determines how much arsenic is in it

Question 7

What is As(V) added to?

Answer 7

Since it is organic it is added to chicken feed to stimulate growth

Question 8

What is CCA and what is it used for?

Answer 8

Chromated Copper Arsenate

Used for pressure treated wood to prevent bacteria from eating it and to preserve the wood

Question 9

What are 3 places you can find As?

Answer 9

1. Drinking water ( levels vary)
2. Ground water (naturally occurring)
3. Tobacco smoke

Question 10

What happens when you mix As(V) and Fe(II)?

Answer 10

Fe(II) is water soluble so when As attaches to it, As will dissolve with the iron in the soil

Question 11

What 2 things drive the reaction of As and Fe?

Answer 11

1. Peat acting a a reducing agent

2. Lower of the water table due to irrigation

Question 12

How do you remove As from drinking water?

Answer 12

By adding Fe(II). Or Fe3O4 so it can precipitate as a salt

Question 13

What conversion has to happen before the removal process can operate?

Answer 13

As3 have to be converted to As5

Question 14

What colour is the arsenic based paint?

Answer 14

Green pigment that releases methyl arsenic when humid and can grow mold