Answer : The enthalpy change of reaction is -1800 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.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The given final reaction is,
The intermediate balanced chemical reaction will be,
(1) 
(2) 
First we will multiply reaction 1 by 2 and reverse reaction of reaction 2 by 3 then adding both the equation, we get :
The expression for final enthalpy is,
![\Delta H=[n\times \Delta H_1]+[n\times (-\Delta H_2)]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5Bn%5Ctimes%20%5CDelta%20H_1%5D%2B%5Bn%5Ctimes%20%28-%5CDelta%20H_2%29%5D)
where,
n = number of moles
![\Delta H=[2mole\times (-1680kJ/mole)]+[3\times -(-520kJ/mole)]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B2mole%5Ctimes%20%28-1680kJ%2Fmole%29%5D%2B%5B3%5Ctimes%20-%28-520kJ%2Fmole%29%5D)
Therefore, the enthalpy change of reaction is -1800 kJ
Answer:
H₂SO₄
Explanation:
We have a compound formed by 0.475 g H, 7.557 g S, 15.107 g O. In order to determine the empirical formula, we have to follow a series of steps.
Step 1: Calculate the total mass of the compound
Total mass = mass H + mass S + mass O = 0.475 g + 7.557 g + 15.107 g
Total mass = 23.139 g
Step 2: Determine the percent composition.
H: (0.475g/23.139g) × 100% = 2.05%
S: (7.557g/23.139g) × 100% = 32.66%
O: (15.107g/23.139g) × 100% = 65.29%
Step 3: Divide each percentage by the atomic mass of the element
H: 2.05/1.01 = 2.03
S: 32.66/32.07 = 1.018
O: 65.29/16.00 = 4.081
Step 4: Divide all the numbers by the smallest one
H: 2.03/1.018 ≈ 2
S: 1.018/1.018 = 1
O: 4.081/1.018 ≈ 4
The empirical formula of the compound is H₂SO₄.
Answer:
96.09 g/mol
Explanation:
You just need to first get the atomic weights of the elements involved. You can easily get these from your periodic table.
If you are going to do this properly, please use the weight with at least two decimal places for accuracy (e.g. 15.99 g/mol).
Also, please take note that I will be using the unit g/mol for all the weights. Thus,
Step 1
N = 14.01 g/mol
H = 1.008 g/mol
O = 16.00 g/mol
C = 12.01 g/mol
Since your compound is
(
N
H
4
)
2
C
O
3
, you need to multiply the atomic weights by their subscripts. Therefore,
Step 2
N = 14.01 g/mol × 2 =
28.02 g/mol
H = 1.008 g/mol × (4×2) =
8.064 g/mol
O = 16.00 g/mol × 3 =
48.00 g/mol
C = 12.01 g/mol × 1 =
12.00 g/mol
To get the mass of the substance, we need to add all the weights from Step 2.
Step 3
molar mass of
(
NH
4
)
2
CO
3
=
(28.02 + 8.064 + 48.00 + 12.01) g/mol
=
96.09 g/mol
this is a google search and a example i hope is helps to solve
The correct option is B.
This question is testing your knowledge of the differences between solid and liquid particles. The particles of the solid vibrate around a fixed position, they can not move about while those of the liquid are able to move to some extent. The candy in Damien's pocket melted because it was heated up by the temperature of his body. Because the particles of the chocolate has been heated, they gain more kinetic energy and they vibrate faster compare to that of the solid chocolate.
Answer:
Explanation:
Hello!
In this case, since the relationship between molecules and mass is first analyzed via the Avogadro's number to compute the moles in the given molecules:
We now use the molar mass of carbon tetrachloride (153.81 g/mol) to obtain the required grams:
Best regards!
