chem Flashcards
(20 cards)
What is the pH scale range?
1 (strong acid) → 7 (neutral) → 14 (strong alkali)
The pH scale quantifies the acidity or alkalinity of a solution.
What is the pH of a neutral solution?
7
Neutral solutions have neither acidic nor alkaline properties.
What color does litmus turn in an acid?
Red
Litmus is a common indicator used to determine acidity or alkalinity.
What color does litmus turn in an alkali?
Blue
This color change indicates the presence of an alkali.
What is vinegar classified as?
Weak acid
Vinegar primarily contains acetic acid, which is not strong.
What is the definition of concentrated?
Little/no water
Concentrated solutions contain a high amount of solute.
What is the definition of dilute?
Lots of water added
Dilute solutions have a low concentration of solute.
True or False: Ammonia is an acid.
False
Ammonia is a base, not an acid.
True or False: Strong acids are always safe if dilute.
False
Even dilute strong acids can be harmful.
What is the pH color range for universal indicator?
Red = pH 1–3, Orange/yellow = weak acid, Green = neutral, Blue = weak alkali, Purple = strong alkali
Universal indicators provide a visual representation of pH levels.
What is the core reaction for neutralisation?
Acid + Alkali → Salt + Water
This reaction forms a salt and water from an acid and an alkali.
Give an example of a neutralisation reaction.
Hydrochloric acid + sodium hydroxide → sodium chloride + water
This is a classic example of neutralisation.
What gas is produced when an acid reacts with a metal?
Hydrogen
This is a common reaction in acid-metal interactions.
What is produced when an acid reacts with a carbonate?
Salt + Water + CO₂
Carbon dioxide gas is released during this reaction.
What is one application of neutralisation in medicine?
Neutralise stomach acid
Antacids are commonly used to alleviate acid reflux.
What is one application of neutralisation in farming?
Neutralise acid soil with lime
Lime is used to raise the pH of acidic soils.
What color would universal indicator show in hydrochloric acid (pH 1)?
Red
This indicates a strong acid.
What color would universal indicator show in vinegar (pH 5)?
Orange/yellow
This indicates a weak acid.
What color would universal indicator show in limewater (pH 9)?
Blue
This indicates a weak alkali.
What color would universal indicator show in oven cleaner (pH 14)?
Purple
This indicates a strong alkali.
