3Ca(s) + 2H3PO4(aq) --> Ca3(PO4)2(s) +3H2(g) How many moles of calcium are required to produce 18.0 g of H2?

What neutral atom is isoelectronic to mn+4

Which of the following are good traits of a hypothesis? it will be able to be testedit can predict an outcomeit will explain the observationsall of these

100 grams of molten lead (600°c) is used to make musket balls. if the lead shot is allowed to cool to room temperature (21°c), what is the change in entropy (in j/k) of the lead? (for the specific heat of molten and solid lead use 1.29 j/g⋅°c; the latent heat of fusion and the melting point of lead are 2.45 × 104 j/kg and 327°c, respectively.)