chemical analysis Flashcards
tests for gas and ions (20 cards)
How do you test for hydrogen?
Place a burning splint at open end of gas - if hydrogen is present it will make a squeaky pop sound (as hydrogen burns rapidly)
How do you test for oxygen?
Use a glowing split and place into tube of oxygen - if oxygen is present it will relight the splint
How do you test for chlorine?
Use damp litmus paper - when it is placed into chlorine gas the litmus paper is bleached and turns white
How do you test for carbon dioxide?
Bubble the gas through lime water (carbon hydroxide aq) and it will turn cloudy
What colour flame is lithium?
Crimson red
What colour flame is sodium?
Yellow
What colour flame is potassium?
Lilac
What colour flame is calcium?
Orange - red
What colour flame is copper?
Green
What does aluminum, calcium and magnesium form with NaOH
White precipitate
What colour precipitate does copper form?
Blue precipitate
What colour precipitate does Iron(II) form?
Green precipitate
What colour precipitate does Iron(III) form?
Brown precipitate
What’s the general equation for these?
Cu2+ + 20H- = Cu(OH)2 (aq)
How do you test for halide ions?
Add dilute nitric acid, followed by silver nitrate solution
What does chloride give?
A white precipitate
What does bromide give?
A cream precipitate
What does iodide give?
A yellow precipitate
How do you test for sulfates?
Add dilute hydrochloric acid followed my barium chloride solution
What forms if sulfates present?
A white precipitate
