Biology quiz
Where is the majority of negative charge on the water molecule?
Oxygen
Acids and bases are key substances in __________.
biology
How many oxygen atoms are in a molecule of water?
1
How many hydrogen atoms are in a molecule of water?
2
How many hydrogen/hydroxide ions are in a neutral liquid?
7
How many hydrogen/hydroxide ions are in acids?
<7
How many hydrogen/hydroxide ions are in bases?
>7
What's a mixture?
A combination of two or more substances in which each substance retains its individual characteristics and properties
What holds the hydrogen atoms to the oxygen atom?
A covalent bond
What kind of charge would the oxygen atom have compared to the hydrogen atoms?
A negative charge
What kind of charge would the hydrogen atoms have compared to the oxygen atom?
A positive charge
What's a homogenous mixture?
A solution
What's a solvent?
A substance in which another substance is dissolved
What's a hydrogen bond?
A weak interaction involving a hydrogen atom and a fluorine, oxygen, or nitrogen atom.
Substances that release hydrogen ions dissolved in water are called
Acids
What are examples of bases?
Antacids, soap, and ammonia
What do the solid lines between the small and large circles represent?
Covalent bonds
Substances that release hydroxide ions when dissolved in water are called
Bases
_____ are weak acids or weak bases that can react with strong acids or strong bases to keep the pH within a particle range.
Buffers
A suspension is a homogeneous mixture in which water is mixed with a substance that does not dissolve in it.
False
A suspension is a mixture that has a uniform composition throughout.
False
In a mixture, the solvent is the substance that is dissolved.
False
What do living things need to survive?
Homeostasis
What's the cause of the attractions between molecules of water
Hydrogen and oxygen are oppositely charged because of unequal charging between electrons
What are examples of acids?
Lemon juice, pineapple juice, vinegar, and stomach acids
What's buffers?
Mixtures that can react with acids or bases to keep the pH within a particular range.
Pure water is _____ and has a pH value of 7.0
Neutral
What is it called when molecules have an unequal distribution of charges (they have oppositely charged regions)
Polar molecules
What's pH?
The measure of concentration of H+ in a solution
What's a solute?
The substance that is dissolved in the solvent
What's an acid?
The substances that release hydrogen ions when dissolved in water (H+)
What are bases?
The substances that release hydroxide ions (OH-) when dissolved in water
How do nonpolar molecules such as fats, oils, and waxes interact with the water?
These substances don't interact with each other because they sit on top off each other.
A mixture is a combination of two or more substances in which each substance retains its individual characteristics.
True
A mixture of sand and water is a heterogeneous mixture
True
In a mixture, the solute is the substance that is dissolved.
True
The more _____ a substance releases, the more acidic the solution becomes.
hydrogen ions
The concentration of hydrogen ions in a solution is called
pH
