I dunno............................................
The reaction between Na2S and CuSO4 will give us the balanced chemical reaction of,
Na2S + CUSO4 --> Na2SO4 + CuS
This means that for every 78g of Na2S, there needs to be 159.6 g of CuSO4. The ratio is equal to 0.4887 of Na2S: 1 of CuSO4. Thus, for every 12.1g of CuSO4, we need only 5.91 g of Na2S. Thus, there is an excess of 9.58 g of Na2S. The answer is letter C.
The products for the complete combustion of a hydrocarbon in excess air is carbon dioxide and water. Any hydrocarbon when reacted with oxygen will always yield the said products. Incomplete combustion, on the other hand, yields carbon monoxide and water.
The overall molecule is Polar because the shape of the molecule is Trigonal Pyramidal, which means it has the lone pair electrons. Becuase of the lone pair the pulling is unequal.
H3O+ has 3 polar bonds.
To know if the bonds are polar or nonpolar find the difference of the element's electronegativity charge.
H has electronegativity charge of 2.2, and O has 3.4.
Always subtract the smaller number from the greater one.
So 3.4 - 2.2 = 1.2
If the difference is from 0-0.4 the bond is nonpolar, but if it's from 0.5-1.9 the bond is polar.
So, 1.2 is polar bond. So H3O+ has 3 polar bonds, and the overall molecule is polar too.
A simple way to know if it's polar or nonpolar is to draw the lewis dot structure, and use VSEPR.
