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
c is the answer a benzene
If pH+ is 7
It is Neutral solution
Answer: 672.2 grams
Explanation:
With 564.1 kJ of heat energy, 
moles of ethanol can be combusted.
So, we need to find the formula mass of ethanol.
- The atomic mass of carbon is 12 g/mol.
- The atomic mass of oxygen is 16 g/mol.
- The atomic mass of hydrogen is 1 g/mol.
- So, the formula mass of ethanol is
g/mol.
Therefore, the mass of ethanol is 
grams.
Reaction between Iron and oxygen to form iron (iii) oxide is written as;
4Fe (s) + 3O2(g) = 2Fe2O3(s)
1mole of iron contains 56 g, hence,
28.1 g of iron contains 28.1/56 = 0.502 moles
To get the moles of iron (iii) oxide formed we use the mole ratio
mole ratio of iron : iron (iii) oxide = 4 : 2
Therefore, moles of iron(iii) oxide will be given by 0.502×2/4 = 0.251 moles
hence, the answer is 0.251 moles of iron(iii) oxide
