Answer: when reactants and products are gases at STP.
Justification:
1) STP stands for standard temperature (0°) and pressure (1 atm).
2) According to the kinetic molecular theory of the gases, and as per Avogadro's principle, equal volumes of gases, at the same temperature and pressure, have the same number of molecules.
3) Since the coefficients in a balanced chemical equation represent number of moles, when reactants and products are gases at the same temperature and pressure, the mole ratios are the same that the volume ratios, and then the coefficients of the chemical equation represent the volume ratios.
We determine the percent by mass of water in the compound by dividing the mass of water by the total mass. The total mass of Na2SO4.10H2O is equal to 322 g. The mass of water is 180 g.
percent by mass of water = (180 / 322)*(100 %) = 55.9%
<span>Evaporation from the oceans is the primary mechanism supporting the surface-to-atmosphere portion of the water cycle</span>
Whereas semidiurnal tides are observed at the equator at all times, most locations north or south of the equator experiencetwo unequal high tides and twounequal low tides per tidal day; this is called a mixed tide and the difference in height between successive high (or low) tides iscalled the diurnal inequality.
