Which equation is correctly balanced: $A.$ $Al(s) + 3O_2(g) rarr Al_2O_3(s);$ $B.$ $Al(s) + 3O_2(g) rarr Al_2O_3(s);$ $C.$ $Al(s) + 3/2O_2(g) rarr Al_2O_3(s);$ $D.$ $2Al(s) + 3O_2(g) rarr 2Al_2O_3(s)?$

$2H_2(g)+O_2(g) rarr 2H_2O(l)$ $36*g$ of reactants, and $36*g$ of products.......... VERSUS....... $H_2(g) + 1/2O_2(g)rarr H_2O(l)$ $18*g$ of reactants, and $18*g$ of products.......... Is mass conserved in each reaction? Well, clearly...

The equation given above is wrongly balanced, so I have to correct it first. $Al^@$ + $Zn(NO_3)_2$ = $Al(NO_3)_3$ + $Zn^@$ (unbalanced) Tallying the atoms based on subscripts, left side:...

I think you would immediately recognize that you had been short-changed. Now looking at the equation, $2Al + 3O_2 rarr 2Al_2O_3$, on each side there are 6 oxygen...

Aluminum is oxidized; oxygen is reduced. What are the elemental oxidation states in $Al_2O_3$?

To check excess and limiting reactants, the number of moles has to be found, and then divided by the coefficient. For the sake of shortening the equations, let us say...

As per the equation , $2$ moles of Aluminum Oxide ($Al_2O_3$) produces $4$ moles of Aluminum ($Al$) and $3$ moles of Oxygen ($O_2$). The ratio of $Al$ to $O$ is...

The limiting reactant is the reactant that is present in less amount. 4 mol of Al need to react completely of 3 mol of Oxygen (according with the reaction you...

$HCl(aq)+H_2O(l)rarr Cu^(2+) + 2NO_3^-$ $Ca(OH)_2(s) stackrel(H_2O)rarr Ca^(2+) +2HO^-$ $Ca(NO_3)_2(s) stackrel(H_2O)rarr Ca^(2+) +2NO_3^-$ $NH_3(aq) +H_2O(l) rightleftharpoonsNH_4^+ + HO^-$ And one of these things is not like the other ones.........

Ammonia is a Bronsted base: $NH_3(aq) + H_2O(l) rightleftharpoons NH_4^+ + OH^-$ $pK_b = 4.75$ I am not going to solve this equation using $pK_b$, but most of the ammonia...

The standard of formation is the enthalpy associated with the formation of 1 mole of substance from its constituent in their standard states under specified conditions. And of course...