What are the characteristics of ideal (or nearly ideal) solutions? o a. they follow raoult's law, which means partial pressure of components a and b in a solution will be pia] = piao! times x[a] and pib-p[bol times x[b] where pia0] and p[bo] are respective vapour pressure in pure form and x[a] and x[b] are respective mole fractions of components a and b ia) and pib) piboj times x1b] where piao] and pibo] o b. the enthalpy of mixing of two components should be zero. this signifies that no heat is released or absorbed during mixing of two pure components to form ideal solution. o c. the volume of mixing of two components should be zero. this means that total volume of solution is equal to the sum of the volume of solute and solution. adding further, it also signifies that there is no occurrence of contraction or expansion of volume while mixing of two components. o d. the solute-solute interaction and solvent-solvent interaction is nearly equal to solute- solvent interaction. o a, b and c o a, b and d o all of the above

most historians agree that gabriel mouton, the vicar of st. paul’s church in lyons, france, is the “founding father” of the metric system. he proposed a decimal system of measurement in 1670. mouton based it on the length of one minute of arc of a great circle of the earth (now called a nautical mile, 1852 meters). he also proposed the swing-length of a pendulum with a frequency of one beat per second as the unit of length (about 25 cm). a pendulum beating with this length would have been fairly easy to produce, thus facilitating the widespread distribution of uniform standards. over the years, his work was revised, improved, and extended by a number of french scientists.

the political sponsor of weights and measures reform in the french revolutionary national assembly was the bishop of autun, better known as talleyrand. under his auspices, the french academy appointed several committees to carry out the work of developing a usable system of weights and measures for france. one of the committees recommended a decimalized measurement system based upon a length equal to one ten-millionth of the length of a quadrant of the earth’s meridian (i.e., one ten-millionth of the distance between the equator and the north pole).