How much Na is needed to react with H2O to
liberate 179 mL H2 gas at STP?
Answer in units of g
Please help me with what formulas to use and what to do.
Write and balance the equation.
Convert 179 mL H2 gas @ STP to mols remembering that 1 mol of a gas occupies 22,400 mL at STP.
Using the coefficients in the balanced equation, convert mols H2 to mols Na. Then convert mols Na to grams. g = mols x atomic mass.
Ah, the chemistry of laughter! Well, to determine the amount of Na needed to react with H2O, we need to take a dive into our periodic table and a splashy equation.
First, let's remember that STP stands for Standard Temperature and Pressure. At STP, the temperature is 0 degrees Celsius and the pressure is 1 atmosphere (or 101.325 kilopascals, if we're being fancy).
Now, let's use our equation:
2 Na + 2 H2O -> 2 NaOH + H2
From this balanced equation, we can see that it takes 2 mol of Na to produce 1 mol of H2 gas.
Since we want to find out the amount of Na in grams, we need to use molar masses. The molar mass of Na is approximately 23 g/mol.
We know that 1 mol of any gas at STP occupies 22.4 L, or 22,400 mL.
So, if 22,400 mL of H2 gas is produced, we can calculate the number of moles of H2 gas using the equation:
mols H2 = volume (in mL) / 22,400 mL/mol
In this case, mols H2 = 179 mL / 22,400 mL/mol.
Next, since the stoichiometry of the equation tells us that 2 moles of Na produce 1 mole of H2 gas, we can use a proportion to find the number of moles of Na:
mols Na / 2 = mols H2
Finally, we can convert moles of Na to grams of Na using the molar mass of Na:
grams Na = molar mass Na × mols Na
Plug in the numbers, follow the steps, stay hydrated (with water, not just by this equation), and you'll find your answer!
To determine the amount of Na (sodium) needed to react with H2O (water) and produce a given volume of H2 (hydrogen) gas at STP (Standard Temperature and Pressure), we need to follow these steps:
1. Write the balanced chemical equation for the reaction between Na and H2O:
2 Na + 2 H2O → 2 NaOH + H2
2. Identify the stoichiometry (coefficients) in the balanced equation:
From the equation, we can see that 2 moles of Na react with 2 moles of H2O to produce 1 mole of H2 gas.
3. Use the given volume of H2 gas (179 mL) to calculate the number of moles of H2:
At STP, the molar volume of any gas is 22.4 L. Therefore, 179 mL is equal to 0.179 L.
Using the ideal gas law, PV = nRT, we can rearrange the equation to n = PV/RT, where:
P = pressure (at STP, it is 1 atm)
V = volume of gas in liters (0.179 L)
R = ideal gas constant (0.0821 L•atm/(mol•K))
T = absolute temperature (273.15 K at STP)
n = (1 atm) * (0.179 L) / [(0.0821 L•atm/(mol•K)) * (273.15 K)]
Calculate n to find the number of moles of H2 gas produced.
4. Convert the number of moles of H2 gas to moles of Na:
From the balanced equation, we know that 2 moles of Na react to produce 1 mole of H2. Therefore, if we have 'x' moles of H2 gas, we need '2x' moles of Na.
Let's use the value of 'n' from step 3 to calculate the number of moles of Na.
5. Convert the moles of Na to grams:
The molar mass (atomic mass) of Na is 22.99 g/mol. Multiply the number of moles of Na by the molar mass to obtain the mass of Na required.
Follow these steps to get the final answer in grams.
To answer this question, we need to use the stoichiometry and molar mass of the given compounds.
Step 1: Write the balanced chemical equation for the reaction between sodium (Na) and water (H2O):
2 Na + 2 H2O → 2 NaOH + H2
This equation tells us that 2 moles of Na react with 2 moles of water to produce 2 moles of sodium hydroxide (NaOH) and 1 mole of hydrogen gas (H2).
Step 2: Calculate the number of moles of water (H2O) using the given volume at STP (Standard Temperature and Pressure):
STP is defined as 1 atmosphere (atm) pressure and 0 degrees Celsius (°C), which is equivalent to 273.15 Kelvin (K).
1 mole of any gas at STP occupies 22.4 liters (L). Therefore, the volume of H2 gas can be converted to moles using the following conversion:
179 mL H2 × (1 L / 1000 mL) × (1 mole H2 / 22.4 L) = n moles H2
Step 3: Determine the amount of Na required to react with 2 moles of water:
From the balanced equation, we established that 2 moles of Na react with 2 moles of water.
1 mole of H2O reacts with 1 mole of Na, so 2 moles of water would require 2 moles of Na.
Step 4: Calculate the amount of Na in grams:
To find the mass of Na needed, we need to multiply the number of moles of Na by its molar mass.
The molar mass of sodium (Na) is approximately 22.99 grams/mole.
mass of Na = n moles of Na × molar mass of Na
Now you can plug in the values and solve for the mass of Na needed to react with the given volume of H2 gas at STP.