Honors Biology Chapter 2 section 2
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- _________ is an unequal sharing of electrons.
- polarity
- Lemon juice pH 1.5 is an example of __________.
- acidic solution
- Lower concentrations of H+ ions than pure water are ________.
- basic solution
- Ammonia, pH 11.5 is an example of what__________.
- basic solution
- __________ is a slight negative charge at one end of a molecule, a slight positive charge at the other end.
- polarity
- pH values that are below 7 are called ______.
- acidic
- __________ are alkaline solutions.
- basic solutions
- What causes polarity in a water molecule?
- A water moolecule is polar because there is an uneven distribution of electrons between the oxygen and hydrogen atoms.
- What determines whether a solution is acidic or basic?
- An acidic solution is a higher concentration of H+ ions with pH values below 7 and a basic solution is lower concentration of H+ with a pH above 7.
- What is the relatonship between cohesion and capillary action?
- Cohesion is an attraction between molecules of the same substance. A capillary action is one of the forces that draw water out of the roots of a plant and up to its stems and leaves. Cohesion holds the column of water together as it rises.
- Name two types of mixtures and describe how they are different.
- A solution which are ions that gradually become dispersed in hot water and a suspension is mixtures of water and nondisolved material.
- What is the relationship between a base and a basic solution?
- A base is a compound that produces hydroxide ions in solution. A basic solution contains lower concentration of H+ ions than pure water and pH values above 7.
- Describe how acidic solutions differ from pure water.
- On the pH scale acidic solutions are below 7 and are increasingly acidic and pure water is at 7 making it neutral.
- What are buffers and why are they important to cells?
- Buffers are weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH. It is important to cells since one of the ways the body controls pH is through dissolved compounds called buffers.
- Chemical reactions that _______________energy often occur spontaneously.
- release
- During a chemical reaction, chemical bonds are_________.
- changing
- Biological catalysts, or enzymes, act by lowering the ________ required for a reaction.
- activation energy
- The reactents of an enzyme-catalyzed reaction are known as ________.
- substrates
- Water is a compund with ___ hydrogen atoms and ___oxygen atoms.
- 2 h and 1 o
- Water has interesting properties. Name 2 and their definitions.
- cohesion-attraction between particles of the sam substance. adhesion- an attraction between molecules of different substances.
- Water is a common particle of____. ____is made up of uniformily mixed substinces.
- solution
- Solutions has how many oarts and what are they.
- 2 - solute- (small size particles) substances added in a small amount and dissolves - solvent - the substance in wich the solute dissolves (substant that dissolves added subs)
- What are two kinds of mixtures?
- Colloid- particles added are larger ex. jello and milk - suspension- nondissolved largest particles added and will seperate if left standing ex. muddy water or blood-plasma and cells
- Water solution can be acidic or ______(basic).
- alkaline
- What is a pH scale?
- measures the concentration of acidity in a water based solution