ACIDS, ALKALIS, PH SCALE Flashcards
(18 cards)
What is an acid?
a chemical that gives off hydrogen ions in water and forms salts by combining with certain metals.
What is an alkali?
a chemical that can dissolve in water, combine with acids to form salts, and make acids less acidic.
What is a base?
a substance that reacts with an acid to neutralise it and produce salt.
Name 4 acids
sulfuric acid, nitric acid, hydrochloric acid, citric acid
Name 4 alkalis
sodium hydroxide, potassium hydroxide, calcium hydrochloride, magnesium hydroxide,
What state are acids found in the lab?
aqueous (aq) (dissolved in water)
Describe the pH scale
is a measure of how acidic/ basic water, 0-14 with 7 being neutral.
Formula for any acids named
H2SO4, HNO3
What happens to the pH when alkali reacts with an acid?
the pH or both solutions moves towards 7.
Which numbers on the pH scale are acidic?
0-6 (0-3 strong acid, 3-6 weak acid)
Which number on the pH scale are alkali?
8-14 (8-10 weak alkali, 10-14 strong alkali)
Which number on the pH scale is neutral?
7
What colour does blue litmus turn from an acid?
Red
What do acids produce when reacting with active metals?
Hydrogen
Where is hydrogen present?
In all types of acids.
What are indicators?
They are used to determine if a solution is acidic or alkaline.
What is the name of the reaction between an acid and a base?
Neutralisation.
What is neutralisation?
The reaction between an acid and a base. Results in there being no excess of hydrogen or hydroxide ions present in the solution.
