From the equation:
4mol Li react with 1 mol O2
Molar mass Li = 7g/mol
mol in 84g Li = 84/7 = 12 mol Li
From the equation - 12 mol Li will react with 3 mol O2
At STP 1 mol O2 has volume = 22.4L
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At STP 3 mol O2 has volume = 3*22.4 = 67.2L O2 gas will react. </span>
It's actually C because the rock cooled fast
Answer:

Explanation:
The relation between Kp and Kc is given below:
Where,
Kp is the pressure equilibrium constant
Kc is the molar equilibrium constant
R is gas constant
T is the temperature in Kelvins
Δn = (No. of moles of gaseous products)-(No. of moles of gaseous reactants)
For the first equilibrium reaction:
Given: Kc = 0.50
Temperature = ![400^oC=[400+273]K=673K](https://tex.z-dn.net/?f=400%5EoC%3D%5B400%2B273%5DK%3D673K)
R = 0.082057 L atm.mol⁻¹K⁻¹
Δn = (2)-(3+1) = -2
Thus, Kp is:

Answer:
Explanation:40 mph = 64.3738 kph
kph/3.6 = m/s
64.3738/3.6 = 17.8816 m/s
30 mins in seconds = 30 x 60 = 1800 s
1800 s x 17.8816 m/s = 32186.88 m or 32.18688 km or 20 miles