According To The Equation 2 Na + 2 H 2 O → 2 NaOH + H 2 2 \text{Na} + 2 \text{H}_2\text{O} \rightarrow 2 \text{NaOH} + \text{H}_2 2 Na + 2 H 2 O → 2 NaOH + H 2 , What Mass Of Na Is Required To Yield 22.4 L Of H 2 \text{H}_2 H 2 At STP? (The Atomic Mass Of Na Is 22.99 U.)A. 1.00 G B. 2.00 G C.
Understanding the Chemical Equation
The given chemical equation is . This equation represents the reaction between sodium (Na) and water (H2O) to produce sodium hydroxide (NaOH) and hydrogen gas (H2). To solve this problem, we need to determine the mass of sodium required to yield 22.4 L of hydrogen gas at Standard Temperature and Pressure (STP).
Standard Temperature and Pressure (STP) Conditions
At STP, the temperature is 0°C (273.15 K) and the pressure is 1 atm. These conditions are used as a reference point for gas laws and calculations.
Avogadro's Law and the Molar Volume of a Gas
Avogadro's Law states that equal volumes of gases at the same temperature and pressure contain an equal number of molecules. The molar volume of a gas at STP is 22.4 L/mol. This means that one mole of any gas at STP occupies a volume of 22.4 L.
Calculating the Number of Moles of Hydrogen Gas
To calculate the number of moles of hydrogen gas, we can use the formula:
n = V / Vm
where n is the number of moles, V is the volume of the gas (22.4 L), and Vm is the molar volume of the gas (22.4 L/mol).
n = 22.4 L / 22.4 L/mol = 1 mol
Calculating the Number of Moles of Sodium Required
From the chemical equation, we can see that 2 moles of sodium are required to produce 1 mole of hydrogen gas. Therefore, the number of moles of sodium required is:
n = 2 mol
Calculating the Mass of Sodium Required
The atomic mass of sodium is 22.99 u (unified atomic mass units). To calculate the mass of sodium required, we can use the formula:
m = n * M
where m is the mass, n is the number of moles, and M is the molar mass.
m = 2 mol * 22.99 g/mol = 45.98 g
Converting the Mass of Sodium to Grams
Since the answer choices are given in grams, we can convert the mass of sodium to grams:
m = 45.98 g
Conclusion
To yield 22.4 L of hydrogen gas at STP, 45.98 g of sodium is required. This calculation is based on the chemical equation, Avogadro's Law, and the molar volume of a gas at STP.
Answer
The correct answer is:
Q: What is the significance of Standard Temperature and Pressure (STP) conditions in gas calculations?
A: STP conditions are used as a reference point for gas laws and calculations. At STP, the temperature is 0°C (273.15 K) and the pressure is 1 atm. These conditions are essential for accurate calculations involving gases.
Q: What is Avogadro's Law, and how is it related to gas calculations?
A: Avogadro's Law states that equal volumes of gases at the same temperature and pressure contain an equal number of molecules. This law is crucial in gas calculations, as it allows us to determine the number of moles of a gas based on its volume.
Q: How do I calculate the number of moles of a gas using Avogadro's Law?
A: To calculate the number of moles of a gas, you can use the formula:
n = V / Vm
where n is the number of moles, V is the volume of the gas, and Vm is the molar volume of the gas (22.4 L/mol at STP).
Q: What is the molar volume of a gas at STP, and how is it used in calculations?
A: The molar volume of a gas at STP is 22.4 L/mol. This value is used to calculate the number of moles of a gas based on its volume.
Q: How do I calculate the mass of a substance required to yield a specific amount of gas at STP?
A: To calculate the mass of a substance required to yield a specific amount of gas at STP, you need to follow these steps:
- Determine the number of moles of the gas required.
- Use the chemical equation to determine the number of moles of the substance required.
- Calculate the mass of the substance required using the formula:
m = n * M
where m is the mass, n is the number of moles, and M is the molar mass.
Q: What is the atomic mass of sodium, and how is it used in calculations?
A: The atomic mass of sodium is 22.99 u (unified atomic mass units). This value is used to calculate the mass of sodium required to yield a specific amount of hydrogen gas at STP.
Q: How do I convert the mass of a substance from units of moles to units of grams?
A: To convert the mass of a substance from units of moles to units of grams, you can use the formula:
m = n * M
where m is the mass, n is the number of moles, and M is the molar mass.
Q: What is the correct answer to the problem of calculating the mass of sodium required to yield 22.4 L of hydrogen gas at STP?
A: The correct answer is 45.98 g.
Conclusion
In this article, we have discussed the frequently asked questions related to calculating the mass of sodium required to yield hydrogen gas at STP. We have covered topics such as Avogadro's Law, molar volume, and atomic mass, and provided step-by-step instructions on how to calculate the mass of a substance required to yield a specific amount of gas at STP.