7F - Acids and alkalis Flashcards
What is a hazard?
Somethin.g that can cause harm
What is a risk?
The chance that a hazard will actually cause harm.
How can risks be reduced?
By taking safety precautions: wearing eye protection when handling dangerous chemicals, tying long hair back when handling a Bunsen burner etc.
What taste do acids have?
Sour
What happens if you add water to a concentrated acid?
It becomes more dilute.
Is citric acid an acid or an alkali?
Acid
Is vinegar acidic or an alkaline?
Acidic
Are fizzy drinks acidic or alkaline?
Acidic
Is car battery acid an acid or an alkali?
Acid
Is toothpaste acidic or alkaline?
Alkaline
Are cleaning products normally acidic or alkaline?
Alkaline
Are metal hydroxide solutions acidic or alkaline?
Alkaline
What is an alkali?
A soluble base.
A base is any substance that neutralizes an acid to form salt and water.
What is a base?
Any substance (soluble or insoluble) that neutralizes an acid to form a salt and water.
What are indicators?
Substances that change colour with pH so can be used to detect acids, alkalis and neutral solutions.
What colour is litmus in an acid?
Red
What colour is litmus in an alkali?
Blue
What colour is litmus when neutral?
Purple
The …. the pH, the more acidic a substance is
The lower the pH, the more acidic a substance is.
What is the pH of neutral solution?
pH 7
What pH do acids have?
Less than pH 7.
What pH do alkalis have?
From 7 - 14.
What is the general equation for a reaction between an acid and an alkali?
Acid + alkali > salt + water
What is the general equation for a reaction between an acid and a base?
Acid + base > salt + water
What are the reactants?
Substances you start with and are written on the left side of the word equations.
What are the products?
the new substances that are made and are written on the right side of the equation.
Name the reactants in this equation:
Hydrochloric acid + sodium hydroxide > sodium chloride + water
Hydrochloric acid + sodium hydroxide
Name the products in this equation:
Hydrochloric acid + sodium hydroxide > sodium chloride + water
Sodium chloride + water
What sign is used in a chemical equation between the reactants and products?
An arrow (never put a ‘=’ sign)
The first name of a salt produced is the name of…
the name of the metal in the alkali or base.
The second name of a salt comes from…
the name of the acid (i.e. hydrochloric acid = chloride)
what is the name of the salt formed from hydrochloric acid and zinc oxide?
Zinc chloride
What is the name of the salt formed when magnesium oxide reacts with nitric acid?
Magnesium nitrate
What is the name of the salt formed when copper oxide reacts with sulfuric acid?
copper sulfate
Are metal cides acidic or basic?
Basic
What are antacids?
Medicines that people take if they have digestion problems caused by too much acid on their stomach, They contain a base that neutralizes the extra acid.
What do farmers do if their soil gets too acidic?
Spread lime (a base) on the soil to neutralize the acid.
How do toothpaste work?
Contains a mild alkali to neutralize the acid in our mouths.
How are acidic gases coming out from power stations treated?
They can be reacted with alkalis to neutralize them.
How is sulfuric acid used to treat rust?
Sulfuric acid reacts with rust (iron oxide = basic) to neutralize it.
