Bio 11: Quiz on Water Properties
What is a hydrogen bond
A weak bond between two molecules results from an electrostatic attraction between a proton in one molecule and an electro-negative atom in the other
What is adhesion and cohesion in terms of water molecules?
Adhesion and cohesion are caused by the bipolarity of water molecules, which occurs when the positively charged side of the molecule comes into constant to the negatively charged side of the molecule, they attract each other and form a bond
Difference between adhesion and cohesion
Adhesion: Attraction between water and another substance Cohesion: Water's attraction to water
What is surface tension?
Cohesive forces between liquid molecules are responsible for surface tension. The molecules at the surface of water don't have other water molecules on all sides of them, thus they cohere more strongly to those directly associated with those next to and below.
Why salt dissolves in water
Covalent bonds of water are stronger than ionic bonds in salt molecules
What is the molecular structure of water?
H2O (2 hydrogen atoms and 1 oxygen atom)
What has the higher density: ice (solid) or liquid water?
Liquid water has the higher density. Ice's molecules are arranged in a tight pattern or lattice, whereas water's molecules are more spread out, thus this causes ice to have a lower density.
Why does a needle left out in the sun get hotter than a bucket of water left out in the sun?
Metals have lower specific heat capacity than water
What is capillary action?
Movement of water within the spaces of a porous material due to the forces of adhesion, cohesion, and surface tension. Capillary action occurs when the adhesion to the walls of a vessel is stronger than the cohesive forces between the liquid molecules
Where is the negative charge on the water molecule and where is the positive charge on the water molecule?
Negative charge on water molecule is located around the oxygen atom, whereas the positive charge on the water molecule is located around the hydrogen atom. Molecules will rotate in order for its positive or negative charge to face directly across from the opposite charge of another molecule
Why is water cohesive
Positive charge of hydrogen atom and negative charge of oxygen atom are attracted to each other
Example of surface tension
Small needle floating on surface of water.. needle will sink if surface tension is broken
Difference between solute and solvent
Solvent: Liquid capable of dissolving a variety of other substances, whereas a solute is the substance that gets dissolved
What 2 forces limit height to which capillary action will take water up a tube?
Surface tension and gravity
Example of cohesion
The water drop is composed of water molecules that like to stick together
Example of adhesion
The water drop is stuck to the end of the pine needles
Why is water called the universal solvent?
Water can dissolve more substances than any other liquid
Does water have a low or high specific heat?
Water had a high specific heat of exactly 4.184 J/g celsius, which means that it takes more energy/heat to raise the temperature of water to a certain amount
What makes a water molecule polar?
Water is polar due to its shape, as one side of the water molecule is the positively charged hydrogen atoms and on the other side is the negatively charged oxygen atom
Example of capillary action
Water moving through a paper or cloth towel
Is water a polar covalent bond?
YES
What is a polar covalent bond?
electronegativities of the two atoms are equal
Surface tension
the property of the surface of a liquid that allows it to resist an external force, due to the cohesive nature of the water molecules
