i think that the answer is d. millions of small rocky objects
The energy change if 84.0 g of CaO react with excess water is 98KJ of heat is released.
calculation
heat = number of moles x delta H
delta H = - 65.2 Kj/mol
first find the number of moles of CaO reacted
moles = mass/molar mass
the molar mass of CaO = 40 + 16= 56 g/mol
mass = 84 g
moles therefore = 84 g/56 g/mol =1.5 moles
Heat is therefore = 1.5 moles x -65.2 = - 97.8 Kj = -98 Kj
since sign is negative the energy is released
28%
Explanation:
mass of solute(KBr) = 3.73g
mass of solvent(H2O) = 131g
mass of solution = mass of solute + mass of solvent
= 3.73 + 131
= 134.73g
