Balanced Eqn
2
C
2
H
6
+
7
O
2
=
4
C
O
2
+
6
H
2
O
By the Balanced eqn
60g ethane requires 7x32= 224g oxygen
here ethane is in excess.oxygen will be fully consumed
hence
300g oxygen will consume  
60
⋅
300
224
=
80.36
g
 ethane
leaving (270-80.36)= 189.64 g ethane.
By the Balanced eqn
60g ethane produces 4x44 g CO2
hence amount of CO2 produced =
4
⋅
44
⋅
80.36
60
=
235.72
g
and its no. of moles will be  
235.72
44
 =5.36 where 44 is the molar mass of Carbon dioxide
hope this helps
 
        
             
        
        
        
Answer:
Inside the mouth, these cells are joined together in a sheet. Why are they scattered here? They are scattered here because we disrupted there original form by scrapping them off our mouths and smearing them on the slide.
Explanation:
 
        
             
        
        
        
Answer:
True
Explanation:
The length of covalent bond depends upon the size of atoms and the bond order. 
 
        
             
        
        
        
Answer:
The intermediate is carbocation.
Explanation:
The reaction of alkene with an acid to give alcohol is an electrophilic addition reaction.
In electrophilic reaction, the alkene is being attacked by an alkene.
in case of aqueous acid reaction with alkene , the electrophile is [H⁺].
When the proton attacks the alkene it generates carbocation. 
The carbocation generated is formed based on stability of carbocation.
The mechanism is shown in the figure.
 
        
             
        
        
        
I just looked it up and I found this:
Polar substances are likely to dissolve in polar solvents 
Hope this helps!