Question
A student wants to make a fair comparison of the reactivity of the metals with hydrochiorio aold. (b) Name two variables that must be kept constant. __ 1
Answer
4
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Oliver
Professional · Tutor for 6 years
Answer
1. Temperature2. Concentration of hydrochloric acid.
Explanation
## Step 1: Understand the context of the problem. In this case, the problem is related to a chemistry context. Specifically, it is concerned with a comparative study of different metals' reactiveness with hydrochloric acid. Some known factors/variables exist when comparing the reactivity of different metals: temperature, concentration of the acid, amount/volume of solution, and the surface area of metal. ## Step2: Identify variables to be constant.A 'fair comparison' implies that, except for the type of , other variables should be kept constant. Therefore, for the two variables needs to be provided for this question, we might safely select two among the recognized ones under step 1.Considering it best to choose nuisance variables or confounding variables, they would ideally impact the reaction rates but do not directly relate to the inherent properties of metals themselves. Here, 'temperature' and 'concentration of hydrochloric acid' might be two optimized candidates, as the two factors influence reaction rates but not manifesting the intrinsic reactivity of different metals.### The final choices are: 1. Temperature2. Concentration of hydrochloric acid.