Water, Acids, and Bases Flashcards
what percent of earths water is salt water in our oceans?
97%
what does a covalent bond mean?
they share electrons
what does polar mean?
part of the molecule has a partial negative charge while the other has a partial positive charge.
what atom in H2O has a negative charge? which one has a positive charge?
oxygen is negative and hydrogen is positive.
what is a hydrogen bond?
the positive hydrogen is attracted to the negative oxygen and forms a bond not as strong as a covalent or ionic bond but sometimes turns into one.
what is cohesion?
the H2O molecules stick together because of hydrogen bonds and this causes surface tension, raindrops, and water to be a liquid at room temp.
what is adhesion?
when molecules stick to other molecules
is ice more or less dense than water?
less
what is a solution?
a homogeneous mixture aka a mixture with evenly distributed molecules
what is a solvent?
the substance that makes up most of the solution
what is a solute?
the substance that makes up less of the solution
what is an aqueous solution?
a solution where the solvent is water
how many protons and electrons does hydrogen have?
one of each
what is hydronium?
H3O+ or H+
what is hydroxide?
HO-
what is dynamic equilibrium?
individual molecules change, but on average the mixture stays the same.
what is an acid?
more H3O+ and a lower pH than 7
what is a base?
less H3O+ and higher pH than 7
pH is a logarithmic scale, what does that mean?
pH of 5 is 10x more acidic than a pH of 6
the internal pH of most living cells is?
7 but there are exceptions
what are buffers?
substances that minimize changes in concentrations of H+ and OH– in a solution.
