Which of the following observations would indicate that a material is a pure substance?
it does not dissolve in water.
it changes color after heating,
it cannot be physically broken down into different types of atoms.
it can be physically broken down into different types of molecules

Ethanol (c2h5oh) is produced from the fermentation of sucrose in the presence of enzymes. c12h22o11(aq) + h2o(g) 4 c2h5oh(l) + 4 co2(g) determine the theoretical yield and the percent yields of ethanol if 680. g sucrose undergoes fermentation and 326.5 g ethanol is obtained. theoretical _ g _ percent %

In vapor-liquid equilibrium in a binary mixture, both components are generally present in both phases. how many degrees of freedom are there for such a system? the reaction between nitrogen and hydrogen to form ammonia occurs in the gas phase. how many degrees of freedom are there for this system? steam and coal react at high temperatures to form hydrogen, carbon monoxide, carbon dioxide, and methane. the following reactions have been suggested as being involved in the chemical transformation:

What is the chemical formula of magnesium bromide? a. mgbr2 b. mgbr c. mg2br2 d. mg2br