Which of the following statements about monosaccharide structure is true?
a) aldoses and ketoses differ in the position of their hydroxyl groups.
b) monosaccharides can be classified according to the spatial arrangement of their atoms.
c) all monosaccharides contain carbon, hydrogen, oxygen, and nitrogen atoms.
d) a six-carbon sugar is called a pentose

Iwill give extra points to who gets this right

In a water molecule, hydrogen and oxygen are held together by a(an) bond. a) double covalent b) ionic c) nonpolar covalent d) hydrogen e) polar covalent

)benzene and toluene form nearly ideal solutions. consider an equimolar solution of benzene and toluene. at 20 °c the vapour pressures of pure benzene and toluene are 9.9 kpa and 2.9 kpa, respectively. the solution is boiled by reducing the external pressure below the vapour pressure. calculate (i) the pressure when boiling begins, (ii) the composition of each component in the vapour, and (iii) the vapour pressure when only a few drops of liquid remain. assume that the rate of vaporization is low enough for the temperature to remain constant at 20 °c.