Unit 1: Topic 1 - Structure of Water and Hydrogen bonding Flashcards
Which of the following are important to consider when determining a molecule’s properties?
(A) The atoms that make up the molecule
(B) The sequence of the atoms that make up the molecule.
(C) All of the above
(D) None of the above
(C) All of the above. Both the sequence and the components of molecules help determine the properties of molecules.
Would two proteins with the same amino acids in a different sequence have the same properties?
No
Why are the cohesive and adhesive properties of water important, and what causes them to exist?
The cohesive and adhesive properties of water are important because they allow capillary action (movement of water up a tube against gravity) to happen, which is an essential transport mechanism for life. For example, plants use capillary action to transport water from their roots to their leaves. The cohesive property of water is caused by hydrogen bonding, and the adhesive property of water is caused by the polarity of water.
What is hydrogen bonding?
Hydrogen bonding is the strong attraction that happens between water molecules as a result of the negatively charged oxygen of one water molecule and the positively charged hydrogen of another water molecule.
What is the polarity of water?
The polarity of water is the unequal distribution of charge of a water molecule; oxygen has a negative charge, and hydrogen has a positive charge
Why is water considered a universal solvent, and why is this property of water important?
Water is a universal solvent due to its polarity. Water’s role as a universal solvent is one reason it is essential for life; this property allows water to dissolve and transport materials necessary for life. For example, our kidneys use water to dissolve toxic compounds and transport them out of our body
Why does water have a high heat capacity, and why is this property of water important?
Water has a high heat capacity due to hydrogen bonding. Its high specific heat means water can act as a buffer and absorb heat. Organisms utilize this important property to regulate their temperature.
What are the cohesive and adhesive properties of water and their cause?
Cohesion is the property of water to attract other water molecules. Adhesion is the property of water that causes it to be attracted to other surfaces. Both of these properties are caused by hydrogen bonding.
What is the surface tension of water, and what is its cause?
Surface tension is the tendency of water molecules at the surface of a body of water to be more tightly attracted than other molecules in that body. Essentially, cohesion is stronger than adhesion, so the water molecules at the surface are more attracted to each other than to the air above them. If moving over the surface takes less force than needed to break that attraction, then surface tension allows things, like water strider bugs, to ‘walk on water.’ For example, paper clips can float if placed gently so as to not break that surface attraction but sink if dropped.
