how many grams of Na are needed to react with H2O to liberate 400mL of H2 gas at STP?

Here is a solved example of a stoichiometry problem. Just follow the steps. Remember that 400 mL can be converted to moles by 0.400/22.4 = moles.

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I'm sorry, but I cannot understand what you mean by "5555." Can you please provide more context or information about your question or concern?

Well, have you heard of the saying, "Na, Na, Hey, Hey, Kiss Him Goodbye"? In this case, it's more like "Na, Na, Hey, Hey, React with H2O and Say Goodbye!" Alright, let's do some calculations here.

To determine the amount of Na needed to liberate 400 mL of H2 gas at STP, we need to use a balanced chemical equation. In this case, the balanced equation is:

2Na + 2H2O → 2NaOH + H2

Now, STP stands for Standard Temperature and Pressure, which is 0 degrees Celsius and 1 atmosphere of pressure.

To make things easier, let's use the molar volume of a gas at STP, which is approximately 22.4 L/mol. So, 400 mL is equal to 0.4 L.

From the balanced equation, we see that 2 moles of Na will produce 1 mole of H2 gas.

Now, the molar mass of Na is about 23 g/mol. So, using stoichiometry, we can calculate as follows:

2 moles of Na → 1 mole of H2
x grams of Na → 0.4 L

Cross-multiplying, we get:
0.4 L * 2 moles of Na = 1 mole of H2 * x grams of Na

This gives us:
0.8 moles of Na = x grams of Na

And finally, multiplying the molar mass of Na (23 g/mol) by 0.8 moles, we find that you would need approximately 18.4 grams of Na to liberate 400 mL of H2 gas at STP.

So, grab your clown nose and checkered suspenders, because you'll need about 18.4 grams of Na to make this reaction a comedic success!

To determine the number of grams of Na needed to react with H2O and produce 400 mL of H2 gas at STP (Standard Temperature and Pressure), we need to apply stoichiometry and the concept of molar ratios.

Here's how you can calculate it step by step:

Step 1: Write and balance the chemical equation for the reaction:
2 Na + 2 H2O → 2 NaOH + H2

This equation shows that for every 2 moles of Na, you get 1 mole of H2.

Step 2: Find the molar volume of a gas at STP:
At STP, 1 mole of any ideal gas occupies 22.4 liters or 22,400 mL. So, 1 mole of H2 gas occupies 22,400 mL.

Step 3: Convert the given volume of H2 gas to moles:
400 mL of H2 gas is equal to 400/22,400 = 0.01786 moles of H2.

Step 4: Use the stoichiometry of the balanced equation to find the moles of Na:
From the balanced equation, we see that 2 moles of Na produce 1 mole of H2. So, the moles of Na required will be twice the moles of H2 produced.

0.01786 moles of H2 × 2 moles of Na/1 mole of H2 = 0.03572 moles of Na

Step 5: Calculate the grams of Na:
To convert moles of Na to grams, we need to use the molar mass of Na, which is 22.99 g/mol.

0.03572 moles of Na × 22.99 g/mol = 0.821 grams of Na

Therefore, approximately 0.821 grams of Na are needed to react with H2O to liberate 400 mL of H2 gas at STP.