Answer:
ΔH = +26.08 kJ/mol
Explanation:
The change in enthalpy (ΔH) is given in J/mol, and can be calculated for dissolution by the equation:
ΔH = m(water)*Cp*ΔT/n(solute)
The mass of water is the density multiplied by the volume
m = 1g/mL * 25.0mL = 25.0 g
The number of the moles is the mass divided by the molar mass. Knowing the molar masses of the elements:
N = 14 g/mol x 2 = 28
H = 1 g/mol x 4 = 4
O = 16 g/mol x 3 = 48
NH₄NO₃ = 80 g/mol
n = 1.25/80 = 0.015625 mol
So,
ΔH = 25*4.18*(25.8 - 21.9)/0.015625
ΔH = 26,083.2 J/mol
ΔH = +26.08 kJ/mol
ahí esta la respuesta espero que te sirva
Answer:
34.9 g of Zn(OH)₂ is the maximum mass that can be formed
Explanation:
Let's state the reaction:
ZnO(s) + H₂O(l) → Zn(OH)₂ (aq)
First of all, we need to determine the moles of each reactant and state the limiting:
28.6 g . 1mol /81.38 g = 0.351 moles of ZnO
9.54 g . 1mol /18 g = 0.53 moles of water
As ratio is 1:1, for 0.53 moles of water, we need 0.53 moles of ZnO, but we only have 0.351, so the limiting reactant is the ZnO.
Ratio with the product is also 1:1. From 0.351 moles of oxide we can produce 0.351 moles of hydroxide. Let's calculate the mass:
0.351 mol . 99.4 g /1mol = 34.9 g
The dependent variable depends on the independent variable
I think Alcohol would be the correct answer, but i'm not too sure since my mind is fuzzy about chemistry