ESAT Chemistry Flashcards
6 cards from real ESAT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 ESAT Chemistry flashcards as text
What is the empirical formula of a compound with 40% C, 6.67% H, and 53.33% O by mass?
Answer: CH₂O
Dividing by atomic masses: C:H:O = 40/12 : 6.67/1 : 53.33/16 ≈ 3.33 : 6.67 : 3.33 = 1:2:1 → CH₂O.
In ESAT Chemistry, what does the rate equation r = k[A]²[B] indicate?
Answer: Second order in A and first order in B, third order overall
The rate equation shows the reaction is second order in A, first order in B, and third order overall.
What is a buffer solution?
Answer: A solution that resists pH change on addition of small amounts of acid or base
A buffer solution contains a weak acid and its conjugate base, resisting pH change when small amounts of acid or alkali are added.
Which periodic trend describes the decrease in atomic radius across a period (left to right)?
Answer: Increasing nuclear charge attracting electrons more strongly
Across a period, protons increase while electrons are added to the same shell, so greater nuclear charge pulls electrons closer.
What is produced when an acid reacts with a base?
Answer: Salt and water
An acid-base neutralisation reaction produces a salt and water as products.
What is the standard electrode potential of the standard hydrogen electrode (SHE)?
Answer: 0.00 V
The standard hydrogen electrode is assigned a potential of exactly 0.00 V by convention.