Answer:
is an example of precipitation from a solution.
Explanation:
Correct Question:
A chemist measures the enthalpy change ΔH during the following reaction: Fe(s) + 2HCl(g)-->FeCl2(s) + H2 ΔH=-157.0 kJ. Use this information to complete the table below. Round each of your answers to the nearest kJ/mol
Answer:
-314 kJ
+628 kJ
+157 kJ
Explanation:
The enthalpy change of a reaction measures the amount of heat that is lost or gained by it. If ΔH >0 the heat is gained, and the reaction is called endothermic, if ΔH<0, the heat is lost, and the reaction is called exothermic.
If the reaction is inverted, the value of ΔH is inverted too (the opposite endothermic reaction is exothermic), and if the reaction is multiplied by a constant, ΔH will be multiplied by it too.
1) 2Fe(s) + 4HCl --> 2FeCl2(s) + 2H2(g)
This reaction is the product of the given reaction by 2, so
ΔH = 2*(-157) = -314 kJ
2) 4FeCl2(s) + 4H2(g) --> 4Fe(s) + 8HCl(g)
This reaction is the inverted reaction given multiplied by 4, so
ΔH = 4*(157) = +628 kJ
3) FeCl2(s) + H2(g) --> Fe(s) + 2HCl
This reaction is the inverted reaction given, so
ΔH = +157 kJ
The answer is B) The dependent variable relies upon the independent variable
Answer:The chemical energy
Explanation:because The chemical energy in the food you eat is changed into another kind of chemical energy that your body can use. Your body then uses that energy to give you the kinetic energy that you use in everything you do.
Answer:
A, B, C
Explanation:
Notice that this reaction involves double arrows, meaning this represents an equilibrium reaction in which we observe a forward reaction (combination of hemoglobin and oxygen) and a reverse reaction (decomposition of the oxyhemoglobin complex).
Upon inhalation of oxygen, it accesses the blood of a person and binds to hemoglobin, so the following reaction proceeds to the right.
Similarly, the opposite process takes place in muscles, oxyhemoglobin is decomposed back into hemoglobin and oxygen.
The equilibrium constant reaction is relatively high, since at standard conditions, this is a spontaneous reaction, hemoglobin combines with oxygen without any additional external source of energy.
