Answer:
+26.6kJ/mol
Explanation:
The enthalpy of dissolution of NH₄NO₃ is:
NH₄NO₃(aq) + ΔH → NH₄⁺ + NO₃⁻
Where ΔH is the heat of reaction that is absorbed per mole of NH₄NO₃,
The moles that reacts in 1.60g are (Molar mass NH₄NO₃:80g/mol):
1.60g * * (1mol / 80g) = 0.02 moles reacts
To find the heat released in the coffee cup calorimeter, we must use the equation:
Q = m×ΔT×C
Where Q is heat released,
m is mass of the solution
ΔT is change in temperature (Final temperature - Initial temperature)
C is specific heat of the solution (4.18J/g°C)
Mass of the solution is:
1.60g + 75g = 76.60g
Change in temperature is:
25.00°C - 23.34°C = 1.66°C
Replacing:
Q = m×ΔT×C
Q = 76.60g×1.66°C×4.18J/g°C
Q = 531.5J
This is the heat released per 0.02mol. The heat released per mole (Enthalpy change for the dissolution of NH₄NO₃) is:
531.5J / 0.02mol = 26576J/ mol =
+26.6kJ/mol
<em>+ because the heat is absorbed, the reaction is endothermic-</em>
I'll see what I can do here...
1) Nonmetal
2) Calcium (Ca), chemical element, one of the alkaline-earth metals of Group 2 (IIa) of the periodic table.
3) Hafnium
4) 204.3833 u
5) Not sure what you're asking, but oble gas, any of the seven chemical elements that make up Group 18 (VIIIa) of the periodic table. The elements are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn), and oganesson (Og)
6) The metalloids; boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), polonium (Po) and astatine (At)
7) The Actinide series contains elements with atomic numbers 89 to 103 and is the third group in the periodic table.
8) 33
9) 88
10) 30
Hope this helps!
Answer:
c = 0.898 J/g.°C
Explanation:
1) Given data:
Mass of water = 23.0 g
Initial temperature = 25.4°C
Final temperature = 42.8° C
Heat absorbed = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
Specific heat capacity of water is 4.18 J/g°C
ΔT = 42.8°C - 25.4°C
ΔT = 17.4°C
Q = 23.0 g × × 4.18 J/g°C × 17.4°C
Q = 1672.84 j
2) Given data:
Mass of metal = 120.7 g
Initial temperature = 90.5°C
Final temperature = 25.7 ° C
Heat released = 7020 J
Specific heat capacity of metal = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 25.7°C - 90.5°C
ΔT = -64.8°C
7020 J = 120.7 g × c × -64.8°C
7020 J = -7821.36 g.°C × c
c = 7020 J / -7821.36 g.°C
c = 0.898 J/g.°C
Negative sign shows heat is released.
