Which of the following is a correctly balanced reaction equation?
CaCl2 + NaOH --> NaCl2 + Ca(OH)
CaCl2 + 2NaOH --> 2NaCl +Ca(OH)
CaCl2 + NaOH --> NaCl + Ca(OH)2
2CaCl2 + 4NaOH --> 4NaCl + 2 Ca(OH)2
Just count how many of each atom there are on each side of the equation.
It needs to be the same, for each of the five atoms.