Hey there!
H₃PO₄
Find molar mass.
H: 3 x 1.008 = 3.024
P: 1 x 30.97 = 30.97
O: 4 x 16 = 64
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97.994 grams
The mass of 1 mole of H₃PO₄ is 97.994 grams.
We have 4.5 moles.
97.994 x 4.5 = 440
The mass of 4.5 moles of H₃PO₄ is 440 grams.
Hope this helps!
They are found in group 3 of the periodic table.
Answer:
The answer to your question is P2 = 2676.6 kPa
Explanation:
Data
Volume 1 = V1 = 12.8 L Volume 2 = V2 = 855 ml
Temperature 1 = T1 = -108°C Temperature 2 = 22°C
Pressure 1 = P1 = 100 kPa Pressure 2 = P2 = ?
Process
- To solve this problem use the Combined gas law.
P1V1/T1 = P2V2/T2
-Solve for P2
P2 = P1V1T2 / T1V2
- Convert temperature to °K
T1 = -108 + 273 = 165°K
T2 = 22 + 273 = 295°K
- Convert volume 2 to liters
1000 ml -------------------- 1 l
855 ml -------------------- x
x = (855 x 1) / 1000
x = 0.855 l
-Substitution
P2 = (12.8 x 100 x 295) / (165 x 0.855)
-Simplification
P2 = 377600 / 141.075
-Result
P2 = 2676.6 kPa
Answer: - 436.5 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.
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.
The given chemical reaction is,
Now we have to determine the value of 
for the following reaction i.e,
According to the Hess’s law, if we divide the reaction by half then the will also get halved and on reversing the reaction , the sign of enthlapy changes.
So, the value 
for the reaction will be:
Hence, the value of for the reaction is -436.5 kJ.
