determine the amount of iron in a dietary supplement, a random sample of 15 tablets weighing a total of 23.58 g was ground into a fine powder. A 3.1289 -g sample of the powdered tablets was dissolved and treated to precipitate the iron as Fe(OH)3. The precipitate was collected, rinsed, and ignited to constant weight as Fe2O3, yielding 0.3691 g. calculate the iron content of the dietary supplement as g FeSO4 .7H2O per tablet

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer