| what are cations | positive ions normally metals |
| what are anions | negative ions normally non metals |
| how do you test for cations? | a nichrome wire is dipped into hydrochloric acid HCL. Then dip it into the salt or compound. Hold it above the blue flame on the bunsen burner to get the colour |
| what colour does the cation Li make | red |
| what colour does the cation Na make | yellow |
| what colour does the cation K make | lilac |
| what colour does the cation Ca make | orange or red |
| what colour does the cation Cu make | green |
| how do i Test for cations using Sodium Hydroxide: | Place 1cm3 of element salt into a test tube
Add 1cm3 of Sodium Hydroxide into the tube and record results |
| how many elements are tested for cations using hydrochloric acid | Li, Na, K, Cu , ca |
| how many elements are used for cations using sodium hydroxide | Cu, Fe2, Fe3, NH4 |
| what is made when sodium hydroxide is used for Cu | blue precipitate |
| what is made when sodium hydroxide is used for Fe3 | orange red brown |
| what is made when sodium hydroxide is used for Fe2 | green |
| what is made when sodium hydroxide is used for NH4 | ammonium gas |
| how do i test for halides or anions | if it’s in a salt form you must add nitric acid to make it acidic and get rid of anything that might interfere with the tests.
Once it’s a solution, in a test tube take sample x and add silver nitrate solution into it.
Observe the colour. |
| what three halides are there | bromine chlorine iodine |
| what colour when mixed with silver nitrate does it make for bromine | cream |
| what colour when mixed with silver nitrate does it make for chlorine | white |
| what colour when mixed with silver nitrate does it make for iodine | yellow |
| how do i test for sulfafte ions or anions | If the substance is not as a solution, then add nitric acid to make it into a solution.
Place the solution into a test tube and add some barium chloride solution into it.
If sulfate ions are present, then a white precipitate of Barium Sulfate will form. |
| how do i test for carbonate ions | • Take the substance as a solid or a solution
• Add hydrochloric acid to the solution
• If the limewater solution goes cloudy then carbon dioxide is present.
• This means that the substance contains Carbonate. |
| how do i test for oxygen | Take a glowing splint and place into the test tube.
If it RELIGHTS, then it is present. |
| how do i test for hydrogen | Take a lit splint and place it at the mouth of the test tube.
If it EXPLODES WITH A SQUEAKY POP, then it is present. |
| how do i test for co2 | The carbon dioxide gas is bubbled through calcium hydroxide solution or limewater.
It TURNS CLOUDY AND THERE IS A WHITE PRECIPITATE of (calcium carbonate) AT THE BOTTOM then it is present. |
| how do i test for chlorine | Take a piece of damp litmus paper and hold it over the mouth of the test tube.
If it bleaches the paper and turns it white, then it is present.
h |
| how do i test for ammonia | Take a piece of damp universal paper or a red litmus paper and hold it over the mouth of the test tube.
If it TURNS THE DAMP PAPER BLUE, then it is present. |
