Answer:
There is one single covalent bond between two carbon atoms.
Explanation:
We know that sharing of electrons form covalent bonds.
If we look upon K,L,M ,N shells of the carbon and hydrogen atoms.
We found that Hydrogen is having only
electron in K shell.
And Carbon on the other hand is having
electrons in K shell and
electrons in L shell.
So carbon have
valence electrons,and it can share
bonds with any relevant atom to complete its octet.
And Hydrogen requires
electron to complete its doublet.
Alkane general formula 
For ethane 

Carbon atom is shared by
Hydrogen.
The remaining one electron
of carbon will be shared with another carbon atom.
An image of the sharing of electrons attached below,
Hence we have only
covalent bond between the two.
Answer ————
60.8 g ammonia
Explanation:
Osmosis is the movement of water molecules, across a semipermeable membrane, from a hypotonic solution to a hypertonic solution
Osmosis is critical in the maintenance of the right amount of water in the cells an organism. Water is a universal solvent and is especially important for biochemical activities of a cell. Osmosis maintains the right water homeostasis in cells.
Osmosis is useful in the absorption of water by the roots of the plants and the maintenance of transpirational pull that ensures herbecious plants remain upright.
Osmosis enables the opening and closing of plant stomata hence regulating the loss of water by the plants.
Learn More:
For more on osmosis check out;
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