Answer: The description it provides reactants with sufficient energy for bonds to break and reform best explains the role of activation energy in a chemical reaction.
Explanation:
Activation energy is defined as the minimum amount of required energy so that a chemical reaction can initiate.
As a result, it provides the reactants with certain amount of energy so that they will get the necessary amount of energy to break their bond and then form new bonds.
Thus, we can conclude that the description it provides reactants with sufficient energy for bonds to break and reform best explains the role of activation energy in a chemical reaction.
The heat of the reaction can be calculated using the enthalpy of formation. For a 53.99-g sample of iron, the heat of the reaction is approximately -798.9 kJ.
To calculate the heat of the reaction, we need to use the concept of enthalpy of formation. The enthalpy of formation of Fe2O3(s) is -826.0 kJ/mol. We can use this value as a conversion factor to find the heat produced when 1 mole of Fe2O3(s) is formed. Since we have a 53.99-g sample of iron, we can calculate the moles of iron and use the conversion factor to find the heat of the reaction.
The molar mass of iron (Fe) is 55.845 g/mol. Therefore, the moles of iron in the sample can be calculated as:
(53.99 g) / (55.845 g/mol) = 0.9662 mol
Now, using the conversion factor:
0.9662 mol Fe × (826.0 kJ/mol) = -798.9 kJ
Therefore, the heat of the reaction 4Fe(s) + 3O2(g) → 2Fe2O3(s) when a 53.99-g sample of iron is reacted is approximately -798.9 kJ.
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The problem is solved by first converting the given mass of Fe to moles, then determining the amount of Fe2O3 formed using the stoichiometry of the reaction. With the heat formation of Fe2O3 given, the heat released in the reaction is calculated to be -399.8 kJ, indicating an exothermic reaction.
To solve the given problem, we first need to calculate the number of moles of Fe in the 53.99-g sample. The molar mass of Fe is about 55.85 g/mol, so 53.99 grams will represent approximately 0.967 moles of iron. Given the reaction 4Fe + 3O2 → 2Fe2O3, the formation of 2 moles of Fe2O3 requires 4 moles of Fe; hence a ratio of 2:4= 0.5:1 is formed. So, from 0.967 moles of iron, we get 0.967*0.5 = 0.484 moles of Fe2O3 formed.
From the problem, we know that the heat of formation of Fe2O3 is -826.0 kJ/mol. Therefore, the heat of reaction or released heat from the formation of 0.484 moles will be 0.484*-826.0 kJ/mol = -399.8 kJ. Because the value is negative, this is an exothermic reaction, releasing heat.
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Answer: B. A great deal of heat must be absorbed by water to break hydrogen bonds and allow molecules to move farther apart.
Explanation:
Vaporization is a physical process where liquid state changes to gaseous state.
Water molecules are bonded by strong hydrogen bonding between the hydrogen atom and the electronegative oxygen atom. Thus water molecules present on the surface are strongly attracted by the molecules present below the surface.
Thus as liquid state has to be changed to gaseous state, the heat must be supplied and the reaction will be endothermic.The heat is used to break the inter molecular forces or the hydrogen bonds present in water to convert them to randomly moving gaseous state.
b. The oxygen atom of a water molecule is more electronegative than a hydrogen atom.
c. The hydrogen atoms of a water molecule have a partial negative charge.
d. The hydrogen atom of one water molecule is attracted to the oxygen atom of a different water molecule.
e. The hydrogen atom of a water molecule is attracted to the oxygen atom of the same water molecule.
f. The oxygen atom of a water molecule has a partial positive charge.
g The oxygen atom of a water molecule has a partial negative charge.
Answer:
The answer to your question is below
Explanation:
a. The hydrogen atoms of a water molecule have a partial positive charge. True.
b. The oxygen atom of a water molecule is more electronegative than a hydrogen atom. True
c. The hydrogen atoms of a water molecule have a partial negative charge. False
d. The hydrogen atom of one water molecule is attracted to the oxygen atom of a different water molecule. True
e. The hydrogen atom of a water molecule is attracted to the oxygen atom of the same water molecule. False,
f. The oxygen atom of a water molecule has a partial positive charge. True
g The oxygen atom of a water molecule has a partial negative charge. True
X(g) + 2Y(g) → 2Z(9)
When 3.0 mol of X and 3.0 mol of Y are placed inside a container with a volume of 1.0 dmº, they
react to form the maximum amount of Z.
The final temperature of the reaction vessel is 120°C.
What is the final pressure inside the reaction vessel?
А
4.49 x 10 Pa
B
9.80 x 106 Pa
C
1.47 x 10' Pa
D
1.96 x 10' Pa
Answer:
D
Explanation:
PV=nRT
n=nx + my
n=3mol+3mol
n=6mol
T=120+273=393K
P=nRT/V
P=6×0.0821×393/1
P=193atm
1atm=1.01325×10^5Pa
193atm=xPa
x=1.96×10^7Pa