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
There is 103 percent of water in hydrate
Answer:
K8S4O16 or K8(SO4)4 depending on if the SO4 is supposed to represent sulfate or not
Explanation:
Find the molar mass of K2SO4 first:
2K + S + 4O ≈ 174 g/mol
Divide the goal molar mass of 696 by the molar mass of the empirical formula:
696 / 174 = 4
This means you need to multiply everything in the empirical formula by 4:
K2SO4 --> K8S4O16 or K8(SO4)4 depending on if the SO4 is for sulfate or not
Answer:
time taken to cook on the pressure cooker = 100 seconds = 1.67 mins
Explanation:
