Chapter 10 Science
Why do covalent compounds have lower melting points than ionic compounds?
Less heat is needed to separate their molecules.
Why can't a solution of sugar and water conduct an electric current?
Sugar doesn't form ions.
How do the attractive forces of covalent compounds differ from those of ionic compounds?
The attractive forces are weaker
What happens when acid is added to blue litmus paper?
The paper turns red.
What do living things need in their environment?
a certain pH
What is the interaction that holds atoms and ions together called?
a chemical bond
What would you call a base if all of its molecules break apart in water?
a strong base
What is a compound that increases hydronium ions in solution called?
acid
Foods that taste sour usually contain____
acids
When a strong acid dissolves in water, how many molecules break apart?
all
___used in household cleaners
ammonia
What is a compound that can change color depending on conditions such as pH?
an indicator
What do ionic compounds usually do when they are hit?
break apart
___used in cement
calcium hydroxide
The taste of citrus fruits comes from______acid.
citric
What identifies whether a solution has an acid or a base?
concentration
Many acids are________, which means that they can destroy things
corrosive
What kind of compound is sugar?
covalent
What kind of compound is formed by the sharing of electrons?
covalent compound
What kind of structure does an ionic compound have?
crystal lattice
Because acids form ions, what can they conduct?
electric current
What can an ionic compound conduct after it dissolves in water?
electric current
Which of the following is NOT an indicator?
hydrochloric acid
What kind of ions separate from acids in solution?
hydrogen
What do acids that react with some metals produce?
hydrogen gas
Compounds that have ionic bonds are called
ionic compounds
Strong bonds make______have high melting points.
ionic compounds
An ionic bond is an attraction between oppositely charged
ions
___used in antacids
magnesium hydroxide
Ionic compounds can be formed when ______ react with nonmetals
metals
What is the group of atoms that make up a single unit of a covalent compound called?
molecule
When acids and bases combine to form a neutral solution, it is called a(n) _______ reaction.
neutralization
When a weak acid dissolves in water, how many molecules break apart?
only a few
What can a group of indicators be used to find?
pH
What is the value used to express acidity or basicity called?
pH
What electronic device can be used to find the pH of a solution?
pH paper
What do water molecules do to ions?
pull them apart
H+ ions in an acid and OH- ions in a base combine to form a(n) ____
salt
Another name for table salt is______
sodium chloride
___used in soap
sodium hydroxide
High melting points are the reason that most ionic compounds are_______ at room temperature.
solids
Which of the following is a covalent compound that dissolves in water?
sugar
What does the strength of an acid or base depend on?
the number of molecules that break apart
What kind of electron determines if a compound is covalent or ionic?
valence
H+ ions in an acid and OH- ions in a base combine to form____
water
What do many covalent compounds NOT dissolve well in?
water
What do many ionic compounds dissolve easily in?
water
What is formed when an acid neutralizes a base?
water and a salt
What do hydrogen ions bond with to form hydronium ions?
water molecules
What is the pH of a neutral solution such as pure water?
7
What is the pH of an acidic solution?
<7
What is the pH of a basic solution?
>7