Answer:
Hydrogen concentration = 7.94×10^-3 M
Explanation:
from potenz Hydrogen ( pH ) definition
pH = -log[H+]
2.1 = -log[H+]
2.1/-log = -log[H+]/-log
10^-2.1 = [H+]
[H+] = 7.94×10^-3M
Neutralization reaction means the reactants must be one acid and one alkali, and the product will be H2O and metal salt.
The only one satisfying this will be B
Electricity grids will produce surplus power
Cathode Ray experiment to figure out electrons exist -> atoms can be broken up into subatomic particles
Answer:
ΔH of the reaction is -802.3kJ.
Explanation:
Using Hess's law, you can know ΔH of reaction by the sum of ΔH's of half-reactions.
Using the reactions:
<em>(1) </em>Cgraphite(s)+ 2H₂(g) → CH₄(g) ΔH₁ = −74.80kJ
<em>(2) </em>Cgraphite(s)+ O₂(g) → CO₂(g) ΔH₂ = −393.5k
J
<em>(3) </em>H₂(g) + 1/2 O₂(g) → H₂O(g) ΔH₃ = −241.80kJ
The sum of (2) - (1) produce:
CH₄(g) + O₂(g) → CO₂(g) + 2H₂(g) ΔH' = -393.5kJ - (-74.80kJ) = -318.7kJ
And the sum of this reaction with 2×(3) produce:
CH₄(g) + 2 O₂(g) → CO₂(g) + 2H₂O(g) And ΔH = -318.7kJ + 2×(-241.80kJ) =
<em>-802.3kJ</em>
