Answer:
Endothermic: water formation from ice and a cold instant ice pack Explanation:
The question is incomplete,the complete question:
Determine the molality of a 10.0% (by weight) solution of hydrochloric acid in water:
a) 0.274 m
b) 2.74 m
c) 3.05 m
d) 4.33 m
e) the solution's density is necessary for calculations
Answer:
The molality for a 10.0% (by weight) hydrochloric acid solution is 3.05 mol/kg.
Explanation:
The solution is a 10.0% (by weight) hydrochloric acid mix.
This means there are 10 grams of HCl in 100 grams of the solution.
Amount of HCl = 10 g
Total mass of solution = 100 g
Total mass of solution = Mass of solute + Mass of solvent
Mass of solvent (water) = 100 g - 10 g = 90 g
Calculate moles of HCl = 
Mass of water converted to kilograms = 0.090 kg
Molality = 
<strongTherefore, the molality of a 10.0% (by weight) hydrochloric acid solution is 3.05 mol/kg.
Response:
ΔH = -793.6 kJ
Reasoning:
The ΔH for this particular reaction can be calculated through Hess's law, which allows one to combine the ΔH values of the half-reactions to find the overall ΔH:
The half-reactions are as follows:
1) H₂(g) + ¹/₂O₂(g) ⟶ H₂O(g) ΔH₁ = −241.8 kJ
2) X(s) + 2Cl₂(g) ⟶ XCl₄(s) ΔH₂ = +356.9 kJ
3) ¹/₂H₂(g) + ¹/₂Cl₂(g) ⟶ HCl(g) ΔH₃ = −92.3 kJ
4) X(s) + O₂(g) ⟶ XO₂(s) ΔH₄ = −639.1 kJ
5) H₂O(g) ⟶ H₂O(l) ΔH₅ = −44.0 kJ
The calculation involves summing (4) + 4×(3) - (2) - 2×(1) - 2×(5):
(4) X(s) + O₂(g) ⟶ XO₂(s) ΔH = −639.1 kJ
+4×(3) 2H₂(g) + 2Cl₂(g) ⟶ 4HCl(g) ΔH = −369.2 kJ
-(2) XCl₄(s) ⟶ X(s) + 2Cl₂(g) ΔH = -356.9 kJ
-2×(1) 2H₂O(g) ⟶ 2H₂(g) + O₂(g) ΔH = +483.6 kJ
-2×(5) 2H₂O(l) ⟶ 2H₂O(g) ΔH = +88.0 kJ
= XCl₄(s) + 2H₂O(l) ⟶ XO₂(s) + 4HCl(g)
<pThus, ΔH is:
ΔH = -639.1 kJ -369.2 kJ -356.9 kJ +483.6 kJ +88.0 kJ
ΔH = -793.6 kJ
I trust this clarifies things!
Answer: The enthalpy change for the reaction is, 201.9 kJ
Explanation:
Based on Hess’s law of constant heat summation, the energy released or absorbed in a chemical reaction stays constant, regardless of whether the process unfolds in one step or multiple steps.
This principle implies, that chemical equations can be treated analogously to algebraic expressions, allowing addition or subtraction to create the needed equation. Thus, the overall enthalpy change corresponds to the summation of the individual enthalpy changes of the reactions occurring in between.
The balanced equation for
appears as follows,

The intermediate balanced reactions are outlined as follows,
(1)

(2)

(3)

(4)

Next, we will multiply the first reaction by 2, reverse the second, and reverse and halve the third and fourth reactions before combining them. This gives us:
(1)

(2)

(3)

(4)

Therefore, the expression for the enthalpy of the reaction is,



Hence, the enthalpy change for this reaction is, 201.9 kJ
Explanation:
Here’s the provided information:
Density of gasoline = 0.77 g/ml
Volume of gasoline = 35 L = 35000 ml (since 1 L = 1000 ml)
Density of a substance is defined as its mass divided by its volume.
Mathematically, Density =
.
<pthus we="" can="" determine="" the="" mass="" of="" specified="" gasoline="" as="" follows:="">
Density = 
0.77 g/ml = 
mass = 26950 g.
It is further noted that burning 1 g of gasoline generates 45.0 kJ of energy.
<pconsequently the="" energy="" produced="" by="" burning="" g="" of="" gasoline="" will="" be="" calculated="" as="" follows:="">

= 1212750 kJ.
<pthus we="" conclude="" that="">the energy released by combusting 35 L of gasoline amounts to 1212750 kJ.
</pthus></pconsequently></pthus>