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BJ Chem Ch on Water
Question | Answer |
---|---|
What intermolecular bond types do water molecules exhibit? | hydrogen bonding, dipole-dipole, dispersion |
What type of intramolecular bond type does water exhibit? | covalent polar (O-3.5, H-2.1) |
Is water polar or nonpolar? | polar |
What shape is a water molecule? | Tetrahedral with 104.5 degree angles due to 2 sets of unbonded electrons |
What type of bonding raises melting and boiling points? | hydrogen bonding |
A graphical way to summarize the conditions under which a substance exists as a solid, liquid, or gas. | phase diagram |
set of conditions where a substance can exist in all three states: solid, liquid, and gas | triple point |
On a phase diagram, what variable is on the X axis | Temperature (degrees C) |
On a phase diagram, what variable is on the Y axis | Pressure (torr) |
Water is most dense at what temperature (at 1 atm) | 4 degrees C |
Why is water ice less dense as a solid? | hydrogen bonds hold water molecules in an open hexagonal crystalline structure |
water purification step where they precipitate out impurities and bacteria | coagulation and settling |
water purification step where they add chlorine to kill bacteria | disinfection |
water puriciation step where they pass the water through a bed of sand/gravel | filtration |
Name one approach to providing fresh water from the oceans | distillation, vacuum distillation, reverse osmosis, freezing |
Name one approach for bringing fresh water down from Alaska | pipeline, tankers |
When water molecules form is energy consumed or released? | released- exothermic |
the combustion of any hydrocarbon produces ? | CO2 and H2O plus energy |
burning of hydrogen does not produce | CO2 |
Reactions between acids and bases produce ? | a salt and water |
A metal catalyst to decompose water | nickel |
decomposition of water gas with coal produces ? | carbon monoxide CO and H2 gas |
Name a commercial use for hydrogen | production of ammonia, petroleum refining, and as a fuel for NASA space vehicles |
Method to produce pure oxygen and hydrogen from water using electricity | electrolysis |
At which electrode is hydrogen produced? | At the negative Cathode |
At which electrode is oxygen produced? | At the positive anode |
An active metal and water combine to produce ? | a metal hydroxide and hydrogen gas |
A halogen and water combine to produce? | an acid |
Which halogen can displace oxygen in the water molecule | fluorine |
water incorporated into the crystal structure is called the | water of hydration |
Name for CuSO4 - 5 H2O | Copper Sulfate Pentahydrate |
Name for Ba(OH)2 - 8 H2O | Barium hydroxide octahydrate |
substances that can remove water from the air | hygroscopic |
airtight containers to prevent water from the air being absorbed by hygroscopic substances | desiccators |
process of attracting enough water to completely dissolve | deliquescence |
drying agents | dessicants |
Name one drying agent that are also deliquescent | CaCl2, Mg(ClO4)2, and P2O5 |
process where hydrates lose water when exposed to air | efflorescence |
Name one reaction which produces water | acid and base, combustion of hydrogen, combusion to a hydrocarbon |
Which element/ion is put in water supplies to help disinfect the water? | chlorine/chloride |
Which element/ion is put in water supplies to help reduce teeth cavities? | flourine/fluoride |
compounds that can react with water in composition reactions | anhydrides |
metal oxides are called | basic anhydrides |
nonmetal oxides are called | acidic anhydrides |
Potassium oxide is a ______ _________ | basic anhydride |
sulfur dioxide is a _______ ________ | acid anhydride |