Water and buffer Flashcards
Atomic structure determines element behavior.
true
Atoms combine by chemical bonding to form compounds.
false. to form molecules
list some organic compounds.
carbohydrates, fats, proteins, nucleic acids, urea, carbon tetrachloride
list some inorganic compounds.
sodium chloride, brass, glass, carbonates, cyanides, cyanates, carbides, thyocyanates, carbon monoxide, carbon dioxide, water
what is covalent bonds?
Covalent bonds consist of shared pairs of electrons
If one atom is much more electronegative than the other, a complete transfer of one or more electrons can occur
ionic bonds
what is the effects of Water’s Polarity?
polarity results in hydrogen bonding and this gives water its unusual properties
why water has nearly tetrahedral shape?
due to electron pairs repelling each other
Pick the right statement for hydrogen bonds.
- Occurs between a covalently bonded hydrogen and an electronegative atom, usually O or N
- Hydrogen bonds are strong
- hydrogen bonding is not involved in the important properties of water and in macromolecule structure and function (DNA and Proteins)
- Hydrogen bonds form between small molecules or different portions of large molecules
1 and 4. 2. hydrogen are weak. 3. they involved
why does ice floats?
Solid state is usually denser than liquid state. Because molecules are more densely packed. Solid->Melt->molecules move apart -> liquid. But water behaves in an opposite manner
what caused cohesion?
due to the hydrogen bonds that can form between water molecules.
what is adhesion?
Adhesion is the clinging of one substance to another.
- Allows water to move up plants from the roots.
surface tension of water is greater than many liquids.
true. we can see how easy to stretch or break the surface of liquids.
explain why water has high heat capacity.
Water moderates temperatures on Earth. Energy changes required for state change are
significant. Water has a high heat capacity compared to
other liquids. Takes a lot more energy to change the
temperature of water than other liquids.
hydrophilic is water ___ (polar) and hydrophobic is water __ (non-polar).
- loving 2. fearing
Svante Arrhenius defined acids as substances that
dissociate in water to provide hydrogen ions and bases as substances that dissociate in water to provide hydroxide ions
true
what Bronsted-Lowry Theory said about acid and bases?
acids are defined as any hydrogen contain substances capable of donating protons to other substances.
Bases are substances that accept and form covalent bonds with protons.
When a substance behaves as a Bronsted acid by donating a proton the substance becomes a conjugate base and vice versa
why water is considered as an important solvent?
- universal solvent
- biological solvent
- small size
- density of water is greater than ice
- very polar
- hydrogen bonding
Water, a hydrogen-containing material, is able to behave as both a Bronsted acid and a Bronsted base.
true
what do we called when water can behave like an acid or base?
amphiprotic substances
what is autoionization?
when water molecules react with one another to form ions.
list common acids used.
nitric(HNO3), hydrocloric(HCl), sulfuric(H2SO4), acetic(HC2H302)
list common bases used.
ammonium hydroxide(NH4OH), sodium hydroxide(NaOH)
what is the properties of acids?
sour taste, a reaction with water to produce hydronium ions, reacts with solid metallic oxides, hydroxides,
carbonates, and bicarbonates, reacts with certain metals to give hydrogen gas, produce H30+ when dissolved in water
