If 15.8 grams of sodium react with excess water, how many liters of hydrogen gas can be produced at 303 kelvin at 1.30 atmospheres?

6.57 L

Explanation:

First, calculate the moles of hydrogen produced, then use the Ideal Gas Law to calculate the volume of hydrogen.

Step 1. Write the chemical equation.

: 22.99

           2Na + H₂O ⟶ 2NaOH + H₂

Step 1. Convert grams of Na to moles of Na

Step 2. Use the molar ratio of H₂:Na to convert moles of Na to moles of H₂.

Step 3. Use the Ideal Gas Law to calculate the volume of hydrogen.

pV = nRT

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.