Calculate the number of molecules of hydrogen and carbon present in 4g of methane

Which statement describes evidence of a chemical reaction? a) ice melting eliminate b) water boiling c) lighting a match d) grape juice freezing

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 %

Δu of , in kj/kg, as it isto k, (a)as a of , (b) at , (c) at .