Will energy be added or lost when dioxide gas is changed from a gas state to its solid state

How many moles of carbon dioxide will form if 2.5 moles of c3h8 is burned

Pl what kind of reaction is this? nahco3 + h2o → co2 + naoh + h2o -composition -decomposition -single replacement -double replacement im leaning more toward single replacement. if im wrong can you explain whyy?

A0.10 m aqueous solution of sodium sulfate is a better conductor of electricity than a 0.10 m aqueous solution of sodium chloride. which of the following best explains this observation? (a) sodium sulfate is more soluble in water than sodium chloride. (b) sodium sulfate has a higher molar mass than sodium chloride. (c) to prepare a given volume of 0.10 m solution, the mass of sodium sulfate needed is more than twice the mass of sodium chloride needed. (d) more moles of ions are present in a given volume of 0.10 m sodium sulfate than in the same volume of 0.10 m sodium chloride. (e) the degree of dissociation of sodium sulfate in solution is significantly greater than that of sodium chloride.