Answer : The enthalpy change for the reaction is, 419.5 kJ
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
The given chemical reaction is,
Now we have to determine the enthalpy change for the reaction below:
By reversing and then dividing the reaction by 2, we get the enthalpy change for the reaction.
The expression will be:
Therefore, the enthalpy change for the reaction is, 419.5 kJ
Answer:
a
. eight tenths of her cookies
Explanation:
Let the total number of Lakesha's cookies be represented by x.
So that;
She gave three tenths to Bailey = 
of x
= 
She gave five tenths to Helen = 
of x
= 
Fraction of Lakesha's cookies given away = +
= 
= 
Thus, the fraction of cookies given away by Lakesha is 
.
0.88qt
Explanation:
Given parameters:
Density of ebony wood = 1.174g/ml
Mass of wood = 2.1549lb
Unknown:
Volume of the wood in quarts = ?
Solution:
Density is defined as the mass per unit volume of a substance.
Mass is the quantity of matter the wood contains.
Volume is the space it occupies.
To solve this problem, convert the mass form pounds into grams and plug into the density equation to find volume.
Then convert the volume from mL to quarts.
Density = 
Volume = 
1 pound = 453.592g
2.1549 lb = 2.1549 x 453.592 = 977.5g
Volume = 
= 832.6mL
1 quart = 946.353mL
Therefore 832.6mL x 
= 0.88qt
learn more:
Density brainly.com/question/8441651
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Answer:
<em>Hydrogen.</em>
Explanation:
You've probably seen "
" which is the formula for water. It means that there's 2 hydrogen atoms, and one oxygen atom, in one molecule of water.
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