(1)Write a balanced equation in each case dilute htdrochloric reacts with[i]ZnCO3[ii]CuCO3 (2)Discuss how hydrocarbons contribute to the formation of ozone in the atmosphere

(1) Balanced equations for the reactions of dilute hydrochloric acid with zinc carbonate and copper carbonate are as follows:

[i] Reaction of dilute hydrochloric acid with zinc carbonate:
HCl + ZnCO3 → ZnCl2 + CO2 + H2O

[ii] Reaction of dilute hydrochloric acid with copper carbonate:
2HCl + CuCO3 → CuCl2 + CO2 + H2O

In both cases, hydrochloric acid (HCl) reacts with zinc carbonate (ZnCO3) or copper carbonate (CuCO3) to form the respective metal chloride (ZnCl2 or CuCl2), carbon dioxide (CO2), and water (H2O).

(2) Hydrocarbons primarily contribute to the formation of ozone in the atmosphere through a process known as photochemical smog formation. Here are the steps involved:

1. The release of hydrocarbons: Hydrocarbons are emitted into the atmosphere through various human activities, including combustion of fossil fuels (such as vehicle emissions, industrial processes, and power generation) and natural processes (such as forest fires and vegetation).

2. Reaction with nitrogen oxides (NOx): Hydrocarbons react with nitrogen oxides (NOx), primarily nitrogen dioxide (NO2), in the presence of sunlight to form a group of secondary pollutants called peroxyacyl nitrates (PANs). PANs are powerful respiratory irritants and contribute to the formation of smog.

3. Formation of ground-level ozone: In the presence of sunlight, the hydrocarbons and nitrogen oxides combine to form ground-level ozone (O3). This reaction occurs in the lower atmosphere and is facilitated by the presence of volatile organic compounds (VOCs) emitted from various sources.

It is important to note that ozone present in the stratosphere (high in the atmosphere) is beneficial as it protects us from harmful ultraviolet (UV) radiation. However, ground-level ozone, formed through the reaction described above, can have negative effects on human health and the environment.

To write a balanced equation, we need to ensure that the number of atoms of each element is equal on both sides of the equation. Let's go through each case:

(i) Dilute hydrochloric acid (HCl) reacting with Zinc Carbonate (ZnCO3):

Step 1: Write the chemical formula of each compound:
Hydrochloric acid: HCl
Zinc Carbonate: ZnCO3

Step 2: Identify the products of the reaction:
Hydrochloric acid donates a hydrogen ion (H+) and reacts with the carbonate ion (CO3^2-) to form water (H2O) and zinc chloride (ZnCl2).

Step 3: Write the balanced equation by ensuring the number of atoms of each element is equal on both sides:
HCl + ZnCO3 → ZnCl2 + H2O + CO2

(ii) Dilute hydrochloric acid (HCl) reacting with Copper Carbonate (CuCO3):

Step 1: Write the chemical formula of each compound:
Hydrochloric acid: HCl
Copper Carbonate: CuCO3

Step 2: Identify the products of the reaction:
Hydrochloric acid donates a hydrogen ion (H+) and reacts with the carbonate ion (CO3^2-) to form water (H2O) and copper chloride (CuCl2).

Step 3: Write the balanced equation by ensuring the number of atoms of each element is equal on both sides:
HCl + CuCO3 → CuCl2 + H2O + CO2

Regarding the second question, the formation of ozone in the atmosphere is mainly due to the reaction of hydrocarbons with other atmospheric components. Here's an explanation of how hydrocarbons contribute to ozone formation:

Hydrocarbons are compounds made up of hydrogen and carbon atoms. They are released into the atmosphere through natural sources like forests and wildfires, as well as human activities like burning fossil fuels and industrial processes.

When hydrocarbons are released into the atmosphere, they react with nitrogen oxides (NOx) and sunlight, leading to the formation of secondary pollutants, including ozone (O3). This process occurs in the presence of sunlight and is known as photochemical smog formation.

The primary reaction involved in the formation of ozone from hydrocarbons is called photochemical oxidation. It occurs in multiple steps:

1. Initiation: Sunlight breaks down nitrogen dioxide (NO2) into nitrogen monoxide (NO) and an oxygen atom (O).

2. Propagation: The oxygen atom (O) reacts with oxygen molecules (O2) to form ozone (O3). This is a continuously ongoing process as long as hydrocarbons and nitrogen oxides are present.

3. Termination: Ozone (O3) can be removed from the atmosphere through various reactions, including reactions with nitrogen monoxide (NO) or by simply decomposing back into oxygen molecules (O2).

It's important to note that while some ozone formation is beneficial in the upper atmosphere (stratosphere), where it acts as a shield against harmful ultraviolet (UV) radiation, ozone near the surface (troposphere) is considered a pollutant and contributes to various environmental and health issues.

In summary, hydrocarbons contribute to the formation of ozone in the lower atmosphere through reactions with nitrogen oxides and sunlight, leading to the production of photochemical smog.