You'll want to add three amounts of heat.
(1) Specific heat of lowering the temperature from -135°C to the melting point -114°C
(2) Latent heat of fusion/melting
(3) Specific heat of elevating the temperature from -114°C to -50°C
(1) E = mCΔT = (25 g)(0.97 J/g·°C)(1 kJ/1000 J)(-114 - -135) = 0.509 kJ
(2) E = mΔH = (25 g)(5.02 kJ/mol)(1 mol/46.07 g ethanol) = 2.724 kJ
(3) E = mCΔT = (25 g)(2.3 J/g·°C)(1 kJ/1000 J)(-50 - -114) = 3.68 kJ
<em>Summing up all energies, the answer is 6.913 kJ.</em>
The colored light emitted is energy and in order to emit energy the element should first obtain energy. The energy absorbed by the substance can be in the form of radiation, heat or electricity. Hope this answers the question. Have a nice day.
%Mass
Ar C = 12 g/mol, Mr C₄H₁₀ = 58 g/mol, Ar H = 1 g/mol
or
Answer:
The moles present in 60 g of calcium are 1.5 moles.
Answer:
I. Increasing pressure will allow more frequent successful collision between particles due to the particles being closer together.
II. Rate of reaction increases due to more products being made; as increased pressure favours the exothermic side of the equilibrium.
III. Increasing temperature provides particles lots of (Kinetic) energy, for more frequent successful collision due to the particles moving at a faster rate than before. However, favouring the endothermic side of the equilibrium due to lots of energy required to break and form new bonds.
IV. Rate of reaction increases due to increase temperature favouring both directions of the equilibrium - causing products to form faster.
Hope this helps!
