Zinc metal reacts with hydrochloric acid to produce hydrogen gas. what best describes this reaction?
a. A single replacement reaction takes place because zinc is more reactive and hydrogen
b. A single replacement reaction takes place because zinc is more reactive than chlorine
c. A double replacement reaction takes place because zinc is less reactive than hydrogen
d. A double replacement reaction takes place because zinc is less reactive than chlorine

a. A single replacement reaction takes place because zinc is more reactive and hydrogen

In voltaic series  

Li-K-Ba-Ca-Na-Mg-Al-Mn- (H2O) -Zn-Cr-Fe-Cd-Co-Ni-Sn-Pb- (H) -Cu-Hg-Ag-Pt-Au  

The more to the left, the metal is more reactive (easily release electrons) and the stronger reducing agent  

The more to the right, the metal is less reactive (harder to release electrons) and the stronger oxidizing agent

So that the element located on the left can push the element on the right in the redox reaction

Reaction

Zn+2HCl ⇒ ZnCl₂ + H₂

If we look at this reaction, the elements that play a role are those that undergo a redox reaction

Oxidation : Zn⇒Zn²⁺ + 2e

Reduction : 2H⁺ + 2e ⇒H₂

So Zn (located on the left) can push H (the element on the right) in the redox reaction ⇒ Zn more reactive

A single replacement reaction is a chemical reaction in which one element replaces the other elements of a compound to produce new elements and compounds

A+BC⇒AC+B

So the above reaction involves the elements Zn and H which undergo a redox reaction and are included in a single replacement

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.

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hope i !