Question

note: to answer some of the questions, it may help to reference a periodic table
checkpoint 17
listen
examine the reaction equation.
mg(oh)₂(s) + hcl(aq) → h₂o(l) + mgcl₂(aq)
what coefficients will balance the equation?
1, 2, 3, 1
1, 1, 1, 1
1, 2, 2, 1
2, 4, 2, 2

Explanation:

Step1: Balance Mg

On the left - hand side, there is 1 Mg in \(Mg(OH)_2\), and on the right - hand side, there is 1 Mg in \(MgCl_2\). So the coefficient for \(Mg(OH)_2\) and \(MgCl_2\) can be 1 for now.

Step2: Balance Cl

In \(MgCl_2\), there are 2 Cl atoms. In \(HCl\), there is 1 Cl atom. So we need 2 \(HCl\) molecules to balance the Cl atoms.

Step3: Balance H and O

After putting a coefficient of 2 for \(HCl\), on the left - hand side, for \(H\): \(Mg(OH)_2\) has 2 H (from \(OH\)) and 2 \(HCl\) has 2 H, a total of \(2 + 2=4\) H. On the right - hand side, in \(H_2O\), if we put a coefficient of 2, there are \(2\times2 = 4\) H. For O: \(Mg(OH)_2\) has 2 O, and \(2H_2O\) has 2 O.

The balanced equation is \(Mg(OH)_2(s)+2HCl(aq)\to2H_2O(l)+MgCl_2(aq)\)

Answer:

1, 2, 2, 1