In an experiment to find the percentage conversion of magnesium to magnesium oxide, 0.15g magnesium ribbon was heated in air for 5 minutes. the mass of product found to be 0.22g.

calculate:
a) the number of moles of magnesium at the start of the experiment
b) the mass of oxygen which reacted with magnesium
c) the number of moles of oxygen which reacted.

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.

the number of protons in the nucleus of a given element. has slight luster and conducts electricity at high temperatures like metal.but like a nonmetal,boron is brittle and does not conduct electricity well at low temperatures. in graphite, carbon is a soft,brittle solid.it is reflective,ductile,or malleable.