Acids Flashcards
methyl orange in an acid
red
methyl orange in a neutral solution (such as distilled water)
yellow
methyl orange in an alkali
yellow
phenolphthalein in an acid
colourless
phenolphthalein in a neutral solution (such as distilled water)
colourless
phenolphthalein in an alkali
pink
red litmus paper in an acid
red
red litmus paper in a neutral solution (such as distilled water)
red
red litmus paper in an alkali
blue
blue litmus paper in an acid
red
blue litmus paper in a neutral solution (such as distilled water)
blue
blue litmus paper in an alkali
blue
universal indicator in an acid
red
universal indicator in a neutral solution (such as distilled water)
green
universal indicator in an alkali
blue
How do we measure pH?
using indicators or a pH meter
pH 0-3 are
strong acids
pH 4-6 are
weak acids
pH 7 is
neutral
pH 8-10 are
weak alkalis
pH 11-14 are
strong alkalis
What four main gases make up the air?
nitrogen-78%, oxygen-21%, argon-0.96%, carbon dioxide-0.04%
Name Method 1 of determining the percentage of oxygen in the air
To place an upside down measuring cylinder into water which contains some damp ron wool at the top of it
write a word equation for the reaction that takes place in the iron wool
iron + oxygen + water —> hydrated iron (III) oxide (rust)