Question

For the simple reaction $$ 2 \mathrm{H}_{2}(g)+\mathrm{O}_{2}(g) \rightarrow 2 \mathrm{H}_{2} \mathrm{O}(l) $$ list the types of bonds that must be broken and the types of bonds that must form for the chemical reaction to take place.

Short answer

For the given reaction, the bonds that must be broken are: 1. a single covalent bond in \(H_2\) (hydrogen gas), and 2. a double covalent bond in \(O_2\) (oxygen gas). The bonds that must be formed are two single covalent bonds between hydrogen atoms and oxygen atoms in \(H_2O\) (water).

Step-by-step solution

Identify reactants and products

Reactants are the substances that are present before the reaction, while products are the substances that are formed after the reaction. In this case, the reactants are hydrogen gas (H₂) and oxygen gas (O₂), and the product is water (H₂O).

Identify bonds in reactants

Analyzing the reactants, we can see that hydrogen gas (H₂) consists of two hydrogen atoms bonded together by a single covalent bond, while oxygen gas (O₂) consists of two oxygen atoms bonded together by a double covalent bond.

Identify bonds in products

Analyzing the product, water (H₂O), we can see that it consists of two hydrogen atoms bonded to a single oxygen atom. Each hydrogen atom forms a single covalent bond with the oxygen atom.

Determine bonds that must be broken

For the reaction to occur, the bonds in the reactants must be broken. Therefore, the bonds that must be broken are the single covalent bond in H₂ and the double covalent bond in O₂.

Determine bonds that must be formed

For the product (water) to be formed, new bonds must be created. In this case, two single covalent bonds are formed between the hydrogen atoms and the oxygen atom.

List the types of bonds broken and formed

To summarize, the following types of bonds must be broken and formed for this reaction to occur: - Bonds broken: 1. Single covalent bond in H₂ (hydrogen gas) 2. Double covalent bond in O₂ (oxygen gas) - Bonds formed: 1. Two single covalent bonds between hydrogen atoms and oxygen atoms in H₂O (water)

Key concepts

Covalent Bonds

When atoms share electrons, covalent bonds are formed. These types of bonds are central to the molecules in many substances and are incredibly strong and stable. In the context of the chemical reaction between hydrogen gas ( H₂ ) and oxygen gas ( O₂ ) to form water ( H₂O ), covalent bonds play an essential role.
Initially, hydrogen gas consists of two hydrogen atoms connected by a single covalent bond. This bond results from each hydrogen atom sharing its one electron. Similarly, oxygen gas is composed of two oxygen atoms linked by a double covalent bond. Here, the sharing of two pairs of electrons occurs between the oxygen atoms.
In the outcome of the reaction, water is formed with each hydrogen atom bonding to the oxygen atom through a single covalent bond. This rearrangement signifies the transformation of the original covalent bonds in the reactants to new covalent bonds in the product.

Reactants and Products

In a chemical reaction, reactants are the starting substances, while products are the substances formed as a result of the reaction. Recognizing what constitutes the reactants and products can help understand overall chemical changes.
In our example, the reactants are hydrogen gas ( H₂ ) and oxygen gas ( O₂ ). These are the substances undergoing the transformation. On the other hand, the product is water ( H₂O ), which emerges after the reaction is complete.
This reaction highlights a transformation from gaseous reactants to a liquid product. Such transformations illustrate the rearrangement of atoms, forming new substances with potentially different properties than the initial reactants.

Bond Formation and Breaking

Chemical reactions involve both breaking of bonds in the reactants and the formation of new bonds in the products. This process is vital for the transformation into new substances and is a fundamental concept in chemistry.

• Bond Breaking: Before any new bonds can form, the existing bonds in the reactants need to be broken. For the reaction between H₂ and O₂ , this means breaking the single covalent bond in hydrogen gas and the double covalent bond in oxygen gas. These steps require energy input since breaking stable bonds typically needs energy.
• Bond Formation: Once the original bonds are broken, new bonds form to create the product. In forming water, two new single covalent bonds between hydrogen atoms and the oxygen atom are established. As these bonds form, energy is released, often making the process energetically favorable overall.

Understanding these steps of bond breaking and forming provides insight into how chemical reactions proceed and why energy changes occur during reactions. It clarifies how initial substances change into completely new products with distinctive properties.