Ch.10 - Acids And Bases 1 Flashcards
What are acids?
Acids are substances that turn blue litmus red and neutralise bases. They have a pH scale rating of below 7.
What is the difference between monobasic, dibasic and tribasic acids?
Acids can be classified as monobasic, dibasic or tribasic, depending on the number of hydrogen atoms per molecule that are removable by reaction with a base. HCL is monobasic while H2SO4 is dibasic and H3PO4 is tribasic.
What are bases?
Bases are substances that turn red litmus blue and neutralise acids. A base has a pH of greater than 7. A base that dissolves in water is called an alkali.
What is a neutralisation reaction?
When an acid reacts with a base, a salt is formed.
What is an arrhenius acid?
An acid is a neutral molecule which dissociates in water to form a hydrogen ion. The acidic properties of the solution are due to the presence of H+ ions.
What is an arrhenius base?
An Arrhenius base dissociates in water to form a hydroxide ion. The basic properties of the solution are due to the presence of OH- ions
What is the difference between strong acids and weak acids according to the Arrhenius theory?
In solution, strong acids and bases are fully dissociated and weak acids and bases are only slightly dissociated.
What evidence is there of Arrhenius’ theory of acids and bases?
The Arrhenius theory explains why strong acids conduct electricity only when dissolved in water; there are no ions present in pure acid.
It goes on to explain why a solution of a weak acid or base does not conduct electricity as well as a solution of strong acid or base with similar concentration; there are fewer ions present in the weaker solution
Acids usually need water before they can show their acidic properties.
What limitations does the Arrhenius theory face?
The Arrhenius theory is limited to acid base reactions that take place in water.
When an acid dissolves in water, the hydronium ion (H3O+) is formed rather than the hydrogen ion.
The Arrhenius theory doesn’t explain how certain substances can be amphoteric.
What is a Bronsted-Lowry acid?
A Bronsted-Lowry acid is a proton donor.
What is a Bronsted-Lowry base?
A Bronsted-Lowry base is a proton acceptor.
What happens in an acid-base reaction according to the Bronsted-Lowry theory?
An acid-base reaction involves transfer of a proton (H+) from the acid to the base.
What is the difference between a strong and a weak Bronsted-Lowry acid/base?
A stronger acid/base more readily transfers/accepts a proton. Than a weaker Bronsted-Lowry acid/base.
What are the advantages of the Bronsted-Lowry theory?
It shows how the hydronium ion is formed when an acid reacts with water. The Arrhenius theory only deals with reactions in aqueous solution, while the Bronsted-Lowry theory broadens the scope. For example, ammonia reacts with hydrogen chloride gas in the absence of water.
The Bronsted-Lowry theory explains how some substances can be amphoteric.
What is an amphoteric substance?
An amphoteric substance is one which can react as an acid with a base and as a base with an acid.
