Pls help now quickly . Iron (II) sulfide reacts with oxygen to produce iron (III) oxide and sulfur dioxide. 4 FeS2 (s) + 11 O2(g) →→2 Fe2O3 (s) + 8 SO2 (8)
How many moles of FeS2 are needed to produce 10 moles of Fe2O3?
A. 4
U
B. 5
O
C. 10
D. 20

The formula is (nh4)2co3

The think of process to make something successful

Vander waals forces are inter molecular bonds that exist within molecules of the same substance. a water molecule is made up of oxygen and hydrogen atoms which share electrons between each other. the vander waals forces are forces that exist between multitude of different  molecules of water. dipole dipole forces is the type of vander waals force that exist in water. the oxygen atom which is more electronegative pulls the shared electron closer to itself thus generating a partial negative charge while the hydrogen acquire a partial positive charge. these two different charges causes attraction to occur in water molecules.

Melting increases as mass increases. since alkanes are not branched molecular structures, the one with the heavier mass will have higher melting point.  octane's mp > butane's mp