Answer : The pressure it exert under these new conditions will be, 87 atm
Explanation :
Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.
The combined gas equation is,

where,
= initial pressure of gas = 19 atm
= final pressure of gas = ?
= initial volume of gas = 100 L
= final volume of gas = 20 L
= initial temperature of gas = 
= final temperature of gas = 
Now put all the given values in the above equation, we get:


Therefore, the pressure it exert under these new conditions will be, 87 atm
de Broglie's wave equation describes that particles have wave properties. The equation is
λ = h/mv
Where λ is the wave length of the particle (m), h is the Planck's constant (6.62607 x 10⁻³⁴J s), m is the mass of a particle (kg) and v is the velocity (m/s).
λ = ?
h = 6.62607 x 10⁻³⁴ J s
m =200 g = 0.2 kg
v = 20 m/s
By substitution,
λ = 6.62607 x 10⁻³⁴ J s / (0.2 kg x 20 m/s)
λ = 1.66 x 10⁻³⁴ m
Hence, the wavelength of the 200 g ball 1.66 x 10⁻³⁴ m.
Answer:

Explanation:
Hello!
In this case, for such calorimetry problem, we can notice that the combustion of the compound releases the heat which causes the increase of the temperature by 11.95 °C, it means that we can write:

In such a way, we can compute the total released heat due to the combustion considering the calorimeter specific heat and the temperature raise:

Next, we compute the molar heat of combustion of the compound by dividing by the moles, considering 1.400 g were combusted:

Thus, we obtain:

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