1) Convert 12.9 liters of Oxygen to mol at the given conditions:
PV = nRT ⇒ n = PV/RT
n = [1.2atm*12.9 l] / [0.082 atm l /K mol * 297K]
n = 0.636 mol of O2
2) use the stoichiometry derived from the balanced chemical equation
 1mol C2H4 / 3  mol O2 =  x mol C2H4 / 0.636 mol O2
x = 0.636 / 3 mol O2 = 0.212 mol O2.
Answer: 0.212 mol O2 
        
             
        
        
        
What you were given is the balanced chemical equation
        
             
        
        
        
Explanation:
A process in which water vapor changes into liquid state is known as condensation. As we know that when energy is released in a reaction then it is known as exothermic reaction and when energy is absorbed in a reaction then it is known as endothermic reaction.
As vapors have high energy so, when they change into liquid state then heat energy is released by them. Therefore, condensation is an exothermic reaction.
As per Le Chatelier's principle, any disturbance caused in an equilibrium reaction will tend to shift the equilibrium in a direction away from the disturbance.
So, when there will occur a decrease in temperature then molecules of a gas will come closer to each other. Hence, there will also occur a decrease in vapor pressure of the gas.
 
        
             
        
        
        
Answer:
5kg
Explanation:
Force = Mass x acceleration
F = ma
m = F/a = 10N/2m/s^2 
m = 10/2 = 5kg
The standard unit for mass = Kilogram
 
        
             
        
        
        
Answer:
i) The bond angle decreases due to the presence of lone pairs, which causes more repulsion on the bond pairs and as a result, the bond pairs tend to come closer. ii) The repulsion between electron pairs increases with an increase in electronegativity of the central atom and hence the bond angle increases.
Explanation: