Answer:
13 kJ
Explanation:
Use the following formula where Q is the Joules needed, m is the mass of the substance, c is the heat capacity, and ΔT is the change in temperature.
Q = mcΔT
The heat capacity of water is 4.186 J/g°C. The mass of water is 234 g. The change in temperature is 13.3°C.
Q = mcΔT
Q = (234 g)(4.186 J/g°C)(13.3°C)
Q = 13,027 J
Since the answer is in Joules, convert to kiloJoules.
13,027 J = 13.027 kJ ≈ 13 kJ
I'm going to assume that you mean't mole instead of mile. One mole of O2 has approximately the same mass of one "mole" of N2. I say this because if these elements were rounded by their atomic mass, N would stay as 14, O would round up to 16, and we wouldn't; in this case, O2 would have approximately the same mass as F because F rounds up to 19 and the different between O and N is only 2 while the difference between O and F is 3.
D. uranium: atomic number 92, mass 238, neutrons 146
238-92=146
Ca(OH)2 -------> CaO + H2O
ratio is 1 : 1
CaO Mr= 56g
15/56 = 0.268 mol (mols of CaO in 15g)
Ca(OH)2 Mr= 74g
0.268x74= 19.83g (required amount of Cash(OH)2)
