Balanced equation: 2Al+Fe2O3–> Al2O3+2Fe
Using mole calculations you can find that 10g of Al produces 24.3g of Fe under the conditions described
Robert A. Millikan and Harvey Fletcher performed the oil drop experiment.
Benzene is used for pesticides and detergents. It is also used for other things besides these.
Answer:
pKa = 3.675
Explanation:
∴ <em>C</em> X-281 = 0.079 M
∴ pH = 2.40
let X-281 a weak acid ( HA ):
∴ HA ↔ H+ + A-
⇒ Ka = [H+] * [A-] / [HA]
mass balance:
⇒<em> C</em> HA = 0.079 M = [HA] + [A-]
⇒ [HA] = 0.079 - [A-]
charge balance:
⇒ [H+] = [A-] + [OH-]... [OH-] is negligible; it comes from to water
⇒ [H+] = [A-]
∴ pH = - log [H+] = 2.40
⇒ [H+] = 3.981 E-3 M
replacing in Ka:
⇒ Ka = [H+]² / ( 0.079 - [H+] )
⇒ Ka = ( 3.981 E-3 )² / ( 0.079 - 3.981 E-3 )
⇒ Ka = 2.113 E-4
⇒ pKa = - Log ( 2.113 E-4 )
⇒ pKa = 3.675
Answer:
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- <u><em>C) How much energy was added to the substance to increase molecule motion? </em></u>
Explanation:
<em>The most relevant question to ask regarding this change</em> must take into account the physical knowledge about matter.
When matter changes from<em> liquid </em>state to <em>gaseous</em> state, a physical change called evaporation, the particles (molecules or atoms) of the <em>pure substance </em>will separate from each other, take up more space and move faster.
<em>Condensation</em> is the opposite to evaporation, thus the option A) is not the most relevant question.
<em>The charge of the particles</em> does not change; so the option B) is not relevant at all.
The particles should gain energy from the surroundings to <em>increase</em> their <em>motion</em> (kinetic energy) when they pass from liquid state, where they move slower, to gas state, where they move faster. Hence, the option<em> C), How much energy was added to the substance to increase molecule motion?</em> , is totally relevant.
Since this is an increase in the <em>kinetic energy of the molecules</em>, the option D) is not relevant.
