Answer:
D:2
Explanation:
H is hydrogen, and the subscript represents the amount of atoms it has so H2SO is two hydrogens
A) Initial moles of NH3 = 75/1000 x 0.200 = 0.015 mol
Moles of HNO3 added = 28/1000 x 0.500 = 0.014 mol
NH3 + HNO3 => NH4+ + NO3-
Moles of NH3 left = 0.015 - 0.014 = 0.001 mol
Moles of NH4+ = 0.014 mol
Ka(NH4+) = Kw/Kb(NH3)
= 10-14/1.8 x 10-5 = 5.556 x 10-10
Henderson-Hasselbalch equation:
pH = pKa + log([NH3]/[NH4+])
= -log Ka + log(moles of NH3/moles of NH4+) since volume is the same for both
= -log(5.556 x 10-10) + log(0.0065/0.014)
= 8.14
Answer:
Beryllium-8 (8Be, Be-8) is a radionuclide with 4 neutrons and 4 protons. It is an unbound resonance and nominally an isotope of beryllium. It decays into two alpha particles with a half-life on the order of 10−16 seconds; this has important ramifications in stellar nucleosynthesis as it creates a bottleneck in the creation of heavier chemical elements. The properties of 8Be have also led to speculation on the fine tuning of the Universe, and theoretical investigations on cosmological evolution had 8Be been stable.
Explanation:
The given thermochemical equation is:
Δ
Mass of CO given = 24.0 g
Moles of CO = 
Finding out the heat released to the surroundings when 24.0 g CO:

Therefore, 207 kJ of heat is released to the surroundings when 24.0 g CO reacts completely.