Answer:
5.71 g
Explanation:
Step 1: Write the balanced equation
2 K + Cl₂ ⇒ 2 KCl
Step 2: Calculate the moles corresponding to 12.0 g of KCl
The molar mass of KCl is 74.55 g/mol.
12.0 g × 1 mol/74.55 g = 0.161 mol
Step 3: Calculate the moles of Cl₂ needed to produce 0.161 moles of KCl
The molar ratio of Cl₂ to KCl is 1:2. The moles of Cl₂ needed are 1/2 × 0.161 mol = 0.0805 mol
Step 4: Calculate the mass corresponding to 0.0805 moles of Cl₂
The molar mass of Cl₂ is 70.91 g/mol.
0.0805 mol × 70.91 g/mol = 5.71 g
Answer:
Final temperature: 659.8ºC
Expansion work: 3*75=225 kJ
Internal energy change: 275 kJ
Explanation:
First, considering both initial and final states, write the energy balance:
Q is the only variable known. To determine the work, it is possible to consider the reversible process; the work done on a expansion reversible process may be calculated as:
The pressure is constant, so:
(There is a multiplication by 100 due to the conversion of bar to kPa)
So, the internal energy change may be calculated from the energy balance (don't forget to multiply by the mass):
On the other hand, due to the low pressure the ideal gas law may be appropriate. The ideal gas law is written for both states:
Subtracting the first from the second:

Isolating
:

Assuming that it is water steam, n=0.1666 kmol

ºC
A
Hope this helped thanks u
Answer:
Energy from the chemical bonds of the reactants is released to the surrounding.