Answer:
11419 J/g/ 11.419 KJ/g
Explanation:
H=MCQ
H=225×2.03×(-15-10)
H=225×2.03(25) Note; negative sign is of no use
H=11419J/g
Answer:
pH = 1.32
Explanation:
H₂M + KOH ------------------------ HM⁻ + H₂O + K⁺
This problem involves a weak diprotic acid which we can solve by realizing they amount to buffer solutions. In the first deprotonation if all the acid is not consumed we will have an equilibrium of a wak acid and its weak conjugate base. Lets see:
So first calculate the moles reacted and produced:
n H₂M = 0.864 g/mol x 1 mol/ 116.072 g = 0.074 mol H₂M
54 mL x 1L / 1000 mL x 0. 0.276 moles/L = 0.015 mol KOH
it is clear that the maleic acid will not be completely consumed, hence treat it as an equilibrium problem of a buffer solution.
moles H₂M left = 0.074 - 0.015 = 0.059
moles HM⁻ produced = 0.015
Using the Henderson - Hasselbach equation to solve for pH:
ph = pKₐ + log ( HM⁻/ HA) = 1.92 + log ( 0.015 / 0.059) = 1.325
Notes: In the HH equation we used the moles of the species since the volume is the same and they will cancel out in the quotient.
For polyprotic acids the second or third deprotonation contribution to the pH when there is still unreacted acid ( Maleic in this case) unreacted.
Resonance in air columns is used in a variety of musical woodwind instruments. Something like a flute for example uses resonance to make sound. Not sure what instruments you are talking about unless you provide a list.
They can decay through one of three ways:
alpha decay
beta decay and
gamma decay
ALPHA- particle with two neutrons and two protons is ejected from the nucleus of the radioactive atom. this particle released is called an alpha particle. Only occurs with heavy metals.
BETA- pretty much when a proton is transformed into a neutron, or vise versa. in a beta minus decay, the nuetron decays into a proton and in a beta plus decay, a proton decays into a neutron
GAMMA- the nucleus changes from a high energy state to a low energy state by releasing electromagnetic radiation (photons). the number of protons and neutrons stay the same during this reaction therefore the element is still the same.
