I would say letter C.
"the oxygen atom<span> attracts </span>electrons<span> a bit </span>more<span> strongly </span>than the hydrogen atoms. The unequal sharing of electrons<span> gives the </span>water<span> molecule a slight </span>negative charge<span> near its </span>oxygen atom <span>and a slight </span>positive charge<span> near its </span>hydrogen atoms<span>." (middleschoolchemistry.com)</span>
1°/ . 2 Al + 6 HCl → 2 AlCl3 + 3 H2
<span>k1 = n(Al) / 2 = 4,5 / 2 = 2,25 </span>
<span>k2 = n(HCl) / 6 = 11,5 / 6= 1,92 </span>
<span>k2 < k1 ==> HCl is the limiting reactant </span>
<span>6 mol of HCl ---> 2 mol of H2 </span>
<span>11,5 mol of HCl ---> 3,83 mol of H2 </span>
_Mg + _HCL = _MgCl2 + H2
Separate the terms on each side:
_Mg + _HCl = _MgCl2 + H2
Mg- 1 Mg-1
H-1 H-2
Cl-1 Cl-2
Mg is balanced on both sides so move on to the next (put a 1 in the space).
1Mg
There are two H's and two Cl's on the results side, so to balance the equation put a 2 as a coefficient for HCl and it'll all balance out.
2HCl
Balamced equation will be:
1Mg + 2HCL = 1MgCl2 + H2
It's called substantial collaboration dounti