Answer:
0.259 kJ/mol ≅ 0.26 kJ/mol.
Explanation:
- To solve this problem, we can use the relation:
<em>Q = m.c.ΔT,</em>
where, Q is the amount of heat absorbed by ice (Q = ??? J).
m is the mass of the ice (m = 100.0 g).
c is the specific heat of water (c of ice = 4.186 J/g.°C).
ΔT is the difference between the initial and final temperature (ΔT = final T - initial T = 21.56°C - 25.0°C = -3.44°C).
<em>∵ Q = m.c.ΔT</em>
∴ Q = (100.0 g)(4.186 J/g.°C)(-3.44°C) = -1440 J = -1.44 kJ.
<em>∵ ΔH = Q/n</em>
n = mass/molar mass = (100.0 g)/(18.0 g/mol) = 5.556 mol.
∴ ΔH = (-1.44 kJ)/(5.556 mol) = 0.259 kJ/mol ≅ 0.26 kJ/mol.
Answer:
The answer to your question is: letter B
Explanation:
Reaction
Cr2O3(s) + 3CCl4(l) ⇒ 2CrCl3(s) + 3COCl2(g)
From the information given and the reaction, we can conclude that:
Green solid = Cr2O3 (s) "s" means solid
Colorless liquid = CCl4 (l) "l" means liquid and is the other reactant
Purple solid = CrCl3(s) CrCl3 is purple and "s" solid
Then, as a green specks remains it means that the excess reactant is Cr2O3, so, CCl4 is the limiting reactant.
4 get of helium is 1 mole
