The tarnish that forms on objects made of silver is solid silver sulphide. this can be removed by reacting it with aluminium metal to produce silver metal and solid aluminium sulphide. how many moles of the excess reactant remain unreacted after the reaction between 3.4 moles of silver sulphide with 8.1 moles of aluminium metal is finished?

5.83 mol.

Explanation:

2Al + 3Ag₂S → 6Ag + Al₂S₃,

It is clear that 2 mol of Al react with 3 mol of Ag₂S to produce 1 mol of Ag and 1 mol of Al₂S₃.

Al reacts with Ag₂S with (2: 3) molar ratio.

So, 2.27 mol of Al reacts completely with 3.4 mol of Ag₂S with (2: 3) molar ratio.

The reamining moles of excess reactant "Al" = 8.1 mol - 2.27 mol = 5.83 mol.

the child will have heterozygous dominant chromosomes as characters of his father are dominant over the characters of his mother.

the child is heterozygous

the answers would be

the first one and the second one