# Calculate the Mass of Sodium Needed to Produce Hydrogen Gas at STP

## What mass of sodium is required to yield 22.4 L of hydrogen gas at STP?

Given: 22.4 L of hydrogen gas at STP

The atomic mass of sodium is 22.99 u

## Answer:

To calculate the mass of sodium needed to produce 22.4 L of hydrogen gas at STP, we need to follow these steps:

## Step 1: Determine the Moles of Hydrogen Gas

Since 22.4 L of anything at STP is equal to one mole, we already have one mole of hydrogen gas (H2).

## Step 2: Find the Moles of Sodium Required

From the chemical equation 2Na + 2H2O -> 2NaOH + H2, we know that 2 moles of sodium (Na) yield 1 mole of hydrogen gas (H2).

Therefore, to produce one mole of H2, we need 2 moles of Na.

## Step 3: Calculate the Mass of Sodium

Now, we can calculate the mass of sodium required using the formula:

Mass = Moles x Molar Mass

Mass of Na = 2 moles x molar mass of Na

Mass of Na = 2 moles x 22.99 g/mol = 45.98 g

**Therefore, 46.0 grams of sodium (Na) is required to yield 22.4 L of hydrogen gas at STP.**