Hydrogen gas and aqueous zinc chloride are produced by the reaction of aqueous hydrochloric acid and solid zinc . write a balanced chemical equation for this reaction.

1. Write out all the ions/elements and indicate whether they are reactants or products.

Reactants:

Aqueous Hydrochloric Acid: HCl (H has a charge of +1 and Cl has a charge of 1-, so when an ionic bond forms they will form HCl).

Solid Zinc: Zn (since it is a solid zinc with no other forms of elements, the zinc is pure).

Products:

Hydrogen gas: H2 (it has to be H2 because Hydrogen is a diatomic element, and when by itself during reactions, will be H2 instead of H).

Aqueous Zinc Chloride: ZnCl2 (Zn has a charge of 2+ and Cl has a charge of 1-, so through an ionic bond, they will form ZnCl2).

2. Using this information, you can then write out the unbalanced equation.

HCl + Zn -> H2 + ZnCl2

3. Next, indicate their states of matter and any aqueous solutions.

HCl (aq) + Zn (s) -> H2 (g) + ZnCl2 (aq)

4. Try different numbers until you get the same numbers of H, Cl, and Zn on both sides.

2 HCl (aq) + Zn (s) -> H2 (g) + ZnCl2 (aq)

As you can see, the equation contains 2 Hydrogen atoms on both sides, 2 Chloride atoms on both sides, and 1 Zinc atom on both sides. The equation is chemically balanced.

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.