Answer:
8.8g of Al are necessaries
Explanation:
Based on the reaction, 2 moles of Al are required to produce 3 moles of hydrogen gas.
To solve this question we must find the moles of H2 in 11L at STP using PV = nRT. With these moles we can find the moles of Al required and its mass as follows:
<em>Moles H2:</em>
PV = nRT; PV/RT = n
<em>Where P is pressure = 1atm at STP; V is volume = 11L; R is gas constant = 0.082atmL/molK and T is absolute temperature = 273.15K at STP</em>
Replacing:
1atm*11L/0.082atmL/molK*273.15K = n
n = 0.491 moles of H2 must be produced
<em />
<em>Moles Al:</em>
0.491 moles of H2 * (2mol Al / 3mol H2) = 0.327moles of Al are required
<em />
<em>Mass Al -Molar mass: 26.98g/mol-:</em>
0.327moles of Al * (26.98g / mol) = 8.8g of Al are necessaries
The entropy of the given reactions increases (S° > 0):
- 2C2H6(g) + 7O2(g) ----> 4CO2(g) + 6H2O(g) ---> S° > 0.
- NH4Cl(s) ----> NH3(g) + HCl(g) ---> S° > 0.
<h3>What is entropy?</h3>
Entropy measure how disordered a system is. It a measure of how dispersed or random the total energy of a system is. The symbol for entropy is S.
A system in which entropy increases is one in which S° > 0.
The entropy of a system decreases when S° < 0.
Entropy of a system increases (S° > 0) if any change results in an increase in temperature, increase in number of molecules, or an increase in volume.
Considering the given systems, the entropy changes is as follows:
- 2C2H6(g) + 7O2(g) ----> 4CO2(g) + 6H2O(g) ---> S° > 0.
- 2CO2(g) + N2(g) ---->2CO(g) + 2NO(g) --> no change
- 2N2(g) + O2(g) -----> 2N2O(g) ---> decreases
- S (s,rhombic) + 2CO(g) ----> SO2(g) + 2C (s,graphite) ---> no change
- NH4Cl(s) ----> NH3(g) + HCl(g) ---> S° > 0.
In conclusion, an increase in volume and moles of substances results in entropy increase.
Learn more about entropy at: brainly.com/question/26691503
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1.)<span>1.5 atm= 1140mm Hg
2.)190mm Hg= .25 atm
3.)253mm Hg= 0.332895 atm
4.).2 atm =152mm Hg
5.)1.5mm Hg= 0.199984 kPa
6.)190mm Hg= 25.3313 kPa
7.)103.2 kPa= 774.06355mm Hg
8.)153mm Hg= 20.3983 kPa
9.)99.8 kPa= </span>0.9849494 atm
Answer:
It just means that you are supposed to find an object that is not used in a vacuum. For example, a hair-brush is not use in a vacuum lol