Answer:
calcium is a metal and metals are good conductors of electricity as they contain mobile electrons.
Explanation:
Answer: The given statement is false.
Explanation:
Precipitation reaction is defined as the chemical reaction in which two aqueous solution upon mixing together results in the formation of an insoluble solid.
For example, 
Here AgCl is present in solid state so, it is the precipitate.
But it is not necessarily true that two aqueous solutions will always result in the formation of a precipitate.
For example, 
Hence, we can conclude that the statement precipitation reactions always occur when two aqueous solutions are mixed, is false.
Answer:
i) pH = 2
pH = -log(H+)
:- (H+) = 10^(-2)
:- (H+) = 0.01 M
ii) pH = 6
pH = -log(H+)
:- (H+) = 10^(-6)
:- (H+) = 0.000001 M
Explanation:
By definition: pH = -log(H+).
Given your pH, solve for the H+ using the the following log rule:
if a = (+/-) log (b) then
b = 10^((+/-) a).
Also remember unit of concentration is molar (M)
Answer:
ΔG°rxn = +50.8 kJ/mol
Explanation:
It is possible to obtain ΔG°rxn of a reaction at certain temperature from ΔH°rxn and S°rxn, thus:
<em>ΔG°rxn = ΔH°rxn - T×S°rxn (1)</em>
In the reaction:
2 HNO3(aq) + NO(g) → 3 NO2(g) + H2O(l)
ΔH°rxn = 3×ΔHfNO2 + ΔHfH2O - (2×ΔHfHNO3 + ΔHfNO)
ΔH°rxn = 3×33.2kJ/mol + (-285.8kJ/mol) - (2×-207.0kJ/mol + 91.3kJ/mol)}
ΔH°rxn = 136.5kJ/mol
And S°:
S°rxn = 3×S°NO2 + S°H2O - (2×S°HNO3 + S°NO)
ΔH°rxn = 3×0.2401kJ/molK + (0.0700kJ/molK) - (2×0.146kJ/molK + 0.2108kJ/molK)
ΔH°rxn = 0.2875kJ/molK
And replacing in (1) at 298K:
ΔG°rxn = 136.5kJ/mol - 298K×0.2875kJ/molK
<em>ΔG°rxn = +50.8 kJ/mol</em>
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