Answer : The mass of aluminium (Al) is 0.413 g
Solution : Given,
Volume of
at STP = 513 ml = 0.513 L ( 1 L = 1000 ml )
Molar mass of aluminium = 26.98 g/mole
First we have to calculate the moles of
.
At STP,
1 mole occupies 22.4 L volume
now, 0.513 L gives
moles of 
The moles of
= 0.0229 moles
The Net balanced chemical reaction is,

From the balanced chemical reaction, we conclude that
2 moles of Aluminium (Al) produces 3 moles of hydrogen gas
Now the number of moles of aluminium required in 0.0229 moles of hydrogen gas =
= 0.0153 moles
Now we have to calculate the mass of aluminium.
Mass of aluminium = number of moles × Molar mass = 0.0153 moles × 26.98 g/mole = 0.413 g
The mass of aluminium required is 0.413 g.
This uses something called the combined gas law. The combined gas law is as follows: (P1*V1/T1) = (P2*V2/T2)
According to question 2, you are given the following values initially:
P1 = 680 mm Hg * (1 atm/760 mm Hg) = 0.895 atm
V1 = 20.0 L
T1 = 293 K
STP or standard temperature and pressure implies that the other values we know are:
P2 = 1 atm
T2 = 273 K
Our unknown is V2
If we plug in our known values into the combined gas law:
(P1*V1/T1) = (P2*V2/T2)
(0.895 atm * 20.0 L)/293K = (1 atm * X liters)/273 K
0.0611 L*atm/K = (1 atm * X liters)/273 K
16.7 L = X liters
Therefore, the volume occupied at STP is 16.7 liters
This makes sense because the gas would occupy a smaller volume at a lower temperature, since the gas would have a lower average kinetic energy.
I’m really sorry I need points I hope you find an answer
Answer:
it moves faster when heated
An exothermic reaction is a chemical reaction that releases energy by light or heat. It is the opposite of an endothermic reaction. im sorry i only could do one! but hope this helped!