Answer:
D.
Explanation:
Cause the weather made those rocks. Like volcanos and weather.
Solution:
At the equivalence point, moles NaOH = moles benzoic acid
HA + NaOH ==> NaA + H2O where HA is benzoic acid
At the equivalence point, all the benzoic acid ==> sodium benzoate
A^- + H2O ==> HA + OH- (again, A^- is the benzoate anion and HA is the weak acid benzoic acid)
Kb for benzoate = 1x10^-14/4.5x10^-4 = 2.22x10^-11
Kb = 2.22x10^-11 = [HA][OH-][A^-] = (x)(x)/0.150
x^2 = 3.33x10^-12
x = 1.8x10^-6 = [OH-]
pOH = -log [OH-] = 5.74
pH = 14 - pOH = 8.26
The balanced chemical reaction is expressed as follows:
<span>CuCl2 (aq) + 2AgNO3 (aq) → 2AgCl (s) + CuNO32 (aq)
To determine the </span><span>concentration of copper(II) chloride contaminant in the original groundwater sample, we use the final amount of silver chloride that was produced from the reaction and the relation of the substances from the chemical reaction. We calculate as follows:
mmol AgCl = 6.1 mg AgCl ( 1 mmol / 143.35 mg ) = 0.0426 mmol
mmol CuCl2 = </span>0.0426 mmol AgCl ( 1 mmol CuCl2 / 2 mmol AgCl ) = 0.0213 mmol CuCl2
concentration of CuCl2 in the original water sample = 0.0213 mmol CuCl2 / 200.0 mL = 1.0638 x 10^-4 mmol / mL or 1.0638 x 10^-4 mol/L
Answer:
ΔG = - 442.5 KJ/mol
Explanation:
Data Given
delta H = -472 kJ/mol
delta S = -108 J/mol K
So,
delta S = -0.108 J/mol K
delta Gº = ?
Solution:
The answer will be calculated by the following equation for the Gibbs free energy
G = H - TS
Where
G = Gibbs free energy
H = enthalpy of a system (heat
T = temperature
S = entropy
So the change in the Gibbs free energy at constant temperature can be written as
ΔG = ΔH - TΔS . . . . . . (1)
Where
ΔG = Change in Gibb’s free energy
ΔH = Change in enthalpy of a system
ΔS = Change in entropy
if system have standard temperature then
T = 273.15 K
Now,
put values in equation 1
ΔG = (-472 kJ/mol) - 273.15 K (-0.108 KJ/mol K)
ΔG = (-472 kJ/mol) - (-29.5 KJ/mol)
ΔG = -472 kJ/mol + 29.5 KJ/mol
ΔG = - 442.5 KJ/mol
Answer: surface tension
Explanation: the tiny weight of insect is not strong enough to break the surface tension of water. So when insects stands or move on water, their feets creates something like dimples on the surface of water which then spring back to propel the insect forward thereby preventing them from sinking.
