NATURAL ACIDS & BASES
What is citric acid?
This acid makes lemons taste sour.
What is phenolphthalein?
This indicator turns pink in a basic solution.
Scientist who grouped elements into triads.
Johann Döbereiner
What are isotopes?
Atoms with the same protons but different neutrons
Valency means:
combining power of an element
What is formic acid?
This acid is found in ant and bee stings.
What is methyl orange?
This indicator turns red in acid and yellow in base.
Scientist who proposed the Law of Octaves.
John Newlands
The average mass of natural isotopes is called:
relative atomic mass
Valency of oxygen
2
What is lactic acid?
This acid occurs in sour milk products like yogurt and kumys.
What is litmus?
This indicator turns blue in basic solutions and red in acidic solutions.
Scientist who created the periodic table and predicted elements.
Dmitri Mendeleev
The standard atom used for atomic mass comparison.
carbon-12
Write the formula for aluminum oxide.
Al₂O₃
What is acetic acid?
This acid is found in vinegar
What is lemon juice (acid)?
Tea changes from brown to orange when this is added.
Vertical columns in the periodic table are called:
groups
Element X has isotopes: 20 (50%), 21 (25%), 19 (25%). Its Ar is:
20
Write the formula for calcium oxide.
CaO
What are alkaloids (amines)?
These basic compounds found in plants include morphine and nicotine.
Why does lemon change tea color?
Because acid changes the pH and affects pigments in tea.
Horizontal rows in the periodic table are called:
periods
Calculate: If 75% of chlorine is mass 35 and 25% is mass 37, the average mass is:
35.5 amu
Write the formula for iron (III) chloride.
FeCl₃