Question

Fill in the blanks. The volume of \(\mathrm{CO}_{2}\) liberated at \(\mathrm{STP}\) is on thermal decomposition of \(84 \mathrm{~g}\) of sodium bicarbonate.

Short answer

Question: Calculate the volume of CO₂ liberated at STP on thermal decomposition of 84 g of sodium bicarbonate. Answer: The volume of CO₂ liberated at STP on thermal decomposition of 84 g of sodium bicarbonate is 11.2 Liters.

Step-by-step solution

Calculate the number of moles of sodium bicarbonate

First, we need to determine the molar mass of sodium bicarbonate (NaHCO₃). Using the periodic table, we find: Molar mass of Na = 22.99 g/mol Molar mass of H = 1.01 g/mol Molar mass of C = 12.01 g/mol Molar mass of O = 16.00 g/mol Molar mass of NaHCO₃ = 22.99 + 1.01 + 12.01 + (3×16.00) = 84.01 g/mol Next, we will use the given mass of sodium bicarbonate (84 g) to find the number of moles: Number of moles = mass/molar mass = 84 g / 84.01 g/mol = 1 mole

Determine the balanced equation for thermal decomposition of sodium bicarbonate

The balanced chemical equation for the thermal decomposition of sodium bicarbonate is: 2NaHCO₃ → Na₂CO₃ + H₂O + CO₂ Using stoichiometry, we can see that for every 2 moles of NaHCO₃, 1 mole of CO₂ is produced.

Calculate the number of moles of CO₂ produced

Using the stoichiometry from the balanced equation, we can determine the number of moles of CO₂ produced: 1 mole of NaHCO₃ × (1 mole of CO₂ / 2 moles of NaHCO₃) = 0.5 mole of CO₂

Convert moles of CO₂ to volume at STP

At STP (Standard Temperature and Pressure) conditions, 1 mole of any gas occupies 22.4 Liters. To find the volume occupied by 0.5 mole of CO₂ at STP, we can use the formula: Volume = Number of moles × molar volume at STP = 0.5 mole × 22.4 L/mol = 11.2 L So, the volume of CO₂ liberated at STP on thermal decomposition of 84 g of sodium bicarbonate is 11.2 Liters.

Key concepts

Thermal Decomposition

Thermal decomposition is a process where a chemical compound breaks down into simpler substances when heated. This process requires heat to break chemical bonds. Depending on the specific compound, the decomposition can result in the formation of various products. During thermal decomposition, compounds such as sodium bicarbonate decompose to release gases and form new substances.
In the case of sodium bicarbonate (NaHCO₃), thermal decomposition occurs when it is heated, causing it to break down into three different substances: sodium carbonate (Na₂CO₃), water (H₂O), and carbon dioxide (CO₂). The equation for this reaction is:

• 2NaHCO₃ (s) → Na₂CO₃ (s) + H₂O (g) + CO₂ (g)

Thermal decomposition reactions play a significant role in various industrial processes and everyday applications, such as baking, where sodium bicarbonate is used as baking soda.

Sodium Bicarbonate

Sodium bicarbonate, commonly known as baking soda, is a chemical compound with the formula NaHCO₃. It is a white, crystalline powder that is often used as a leavening agent in baking due to its ability to produce carbon dioxide gas when heated or combined with an acid.
Sodium bicarbonate has various applications beyond baking. It is used in household cleaning, as an antacid for relieving heartburn, and in personal care products like toothpaste. In the context of thermal decomposition, sodium bicarbonate breaks down upon heating, releasing water vapor and carbon dioxide gas and leaving behind sodium carbonate as a solid residue.
The release of CO₂ is responsible for increasing the volume of dough or batter in baking, contributing to a light and fluffy texture. Understanding how sodium bicarbonate reacts under heat is essential for both culinary and scientific applications.

Molar Volume at STP

The molar volume of a gas is the volume occupied by one mole of the gas at Standard Temperature and Pressure (STP). STP is defined as a temperature of 0°C (273.15 K) and a pressure of 1 atmosphere (atm).
At these conditions, the molar volume of an ideal gas is approximately 22.4 liters. This means that one mole of any gas, whether it's CO₂, O₂, or any other, will occupy a volume of 22.4 liters at STP.
This concept is particularly useful in stoichiometry when calculating the volumes of gases released or consumed in chemical reactions. For example, in the decomposition of sodium bicarbonate, 0.5 mole of CO₂ is produced, which translates to a volume of 11.2 liters at STP, as each mole occupies 22.4 liters. Understanding molar volume helps in predicting and measuring gas volumes in various scientific experiments and industrial applications.