cations tests Flashcards
1
Q
test for aqueos Cations
A
uses aqueous sodium hydroxide and ammonia
2
Q
process of testing for cations
A
aqueous sodium hydroxide and ammonia forming insoluble hydroxide salts which form as a precipitate
3
Q
what is a precipitate?
A
4
Q
ammonium ion
A
NH4 +
5
Q
sulphate ion
A
SO4^2-
6
Q
Carbonate ion
A
CO3^2-
7
Q
Nitrate ion
A
NO3-
8
Q
hydroxide ion
A
OH-
9
Q
testing NH4 +
A
Ammonia gas produced on heating; turns red litmus blue
10
Q
testing Ca^2+
A
forms White ppt
11
Q
testing Cu^2+
A
Light blue ppt
12
Q
testing Fe^2+
A
Green ppt
13
Q
testing Fe^3+
A
Red-brown ppt.
14
Q
testing Zn^2+
A
White ppt
15
Q
testing for some aqueous cations.
A
begin with solution that contains (Ca 2+ , Cu 2+ , Fe 2+ , Fe 3+ and Zn 2+) ions. Get five test tubes and add 2cm of each then add few drops of aqueous sodium hydroxide followed by an excess. Repeat using aqueous ammonia.
