Answer:
25.7 kJ/mol
Explanation:
There are two heats involved.
heat of solution of NH₄NO₃ + heat from water = 0
q₁ + q₂ = 0
n = moles of NH₄NO₃ = 8.00 g NH₄NO₃ × 1 mol NH₄NO₃/80.0 g NH₄NO₃
∴ n = 0.100 mol NH₄NO₃
q₁ = n * ΔHsoln = 0.100 mol * ΔHsoln
m = mass of solution = 1000.0 g + 8.00 g = 1008.0 g
q₂ = mcΔT = 58.0 g × 4.184 J°C⁻¹ g⁻¹ × ((20.39-21)°C) = -2570.19 J
q₁ + q₂ = 0.100 mol ×ΔHsoln – 2570.19 J = 0
ΔHsoln = +2570.19 J /0.100 mol = +25702 J/mol = +25.7 kJ/mol
Answer:
0.17%
Explanation:
With the equation:
2Cr2O7 2- + C2H5OH + H2O --> 4Cr3+ + 2CO2 + 11H2O
We can assume that every mole of ethanol needs 2 moles of Dichromate to react.
So if in 1L we have 0.05961 moles of dichromate we can discover how many moles we have in 35.46mL
1000 mL - 0.05962 moles
35.46 mL - x
x = 
x = 2,11* 10^-3 moles
As we said earlier, 1 mole of ethanol needs 2 mole of dichromate, so in the solution we have 1,055*10^-3 moles of ethanol. We can discover the mass of ethanol present in the solution.
1 mole - 46g
1.055*10^-3 - y
y = 46 * 1.055*10^-3
y = 0.048 g
To discover the percent of alchol we can use a simple relation
28 g - 100%
0.048 - z
z = 
z = 0.17%
I think the correct answer from the choices listed above is option A. A can of diet soda will float in water while a can of regular sugar soda will sink. This is due to the reason that the regular soda is more dense than the diet soda. Hope this answers the question.
Answer: They are referred to as isotopes, which are a form of an element that has different numbers of neutrons in their nucleus.