Answer:
a) Endothermic
b) T₂ = 53.1 ºC
Explanation:
a) We are told that when the ammonium nitrate dissolves in water the pack gets cold so the system is absorbing heat from the surroundings and by definition it is an endothermic process.
b) Recall that the heat, Q, is given by the formula:
Q = mcΔT where m is the mass of water,
c is the specific heat of water, and
ΔT is the change in temperature
We can determine the value for Q since we are given the heat of solution for the ammonium nitrate. From there we can calculate ΔT and finally answer our question.
Molar mass NH₄NO₃ = 80.04 g/mol
moles NH₄NO₃ = 50.0 g/ 80.04 g/mol = 0.62 mol
Q = 25.4 kJ/mol x 0.62 mol = 15.87 kJ = 15.87 kJ x 1000 J = 1.59 x 10⁴ J
Q = mcΔT ⇒ ΔT = Q/mc
ΔT = 1.59 x 10⁴ J/ (135 g x 4.184 J/gºC ) = 28.1 ºC
T₂- T₁ = ΔT ⇒ T₂ = ΔT + T₁ = 28.1 ºC +25.0 ºC = 53.1 ºC
Answer:
Sn and Ge
Explanation:
To obtain the more metallic element, we compare the group in which both elements are. Generally the element with the lower ionzation energy is he more metallic one.
Ionization energy increases fro left to right across a period. Ionization energy decreases down the group.
1. When comparing the two elements A s and S n , the more metallic element is ______based on periodic trends alone.
Sn has a lower ionization energy so it is the more metallic one.
2. When comparing the two elements G e and S b , the more metallic element is ________ based on periodic trends alone.
Ge has a lower ionizaiton energy compared to Sb. So it is more metallic element than Sb.
Molality= moles of solute /kg of solvent
moles of solute= mass/molar mass
moles of solute= 3.94 g / (342 g/mol)
moles of solute= 0.01 mol
molality= 0.01 mol / 0.285 kg
molality= 0.04 m
C. Of the products is equal to the reactants.
Good luck out there! :)
