Because if they are not balanced, then the amount of reaction is not equal to the amount of the product. You must have the same ratio of atoms on both sides of the equation because we are not losing moles of each element.
Answer:

Explanation:
Hello.
In this case, for the given chemical reaction, in order to compute the grams of cadmium hydroxide that would be yielded, we must first identify the limiting reactant by computing the yielded moles of that same product, by 20.0 grams of NaOH (molar mass = 40 g/mol) and by 0.750 L of the 1.00-M solution of cadmium nitrate as shown below considering the 1:2:1 mole ratios respectively:

Thus, since 20.0 grams of NaOH yielded less of moles of cadmium hydroxide, NaOH is the limiting reactant, therefore the mass of cadmium hydroxide (molar mass = 146.4 g/mol) is:

Best regards.
Answer:
17.4
Explanation:
kasi 15.2
16.2
=17.4 thanks me later pa brainliest din