Question

What is the mass of hydrogen produced when 8.0 g of sodium

reacts with an excess of water to produce hydrogen and sodium
hydroxide? The equation is given.
2 Na + 2 H2O → 2NaOH + H2

Answer 1

Mass = 0.35 g

Step-by-step explanation:

Given data:

Mass of sodium = 8.0 g

Mass of hydrogen produced = ?

Solution:

Chemical equation:

2Na + 2H₂O → 2NaOH + H₂

Number of moles of sodium:

Number of moles = mass/molar mass

Number of moles = 8.0 g/ 23 g/mol

Number of moles = 0.35 mol

now we will compare the moles of sodium and hydrogen

Na : H₂

2 : 1

0.35 : 1/2×0.35 = 0.175 mol

Mass of hydrogen:

Mass = number of moles × molar mass

Mass = 0.175 mol × 2 g/mol

Mass = 0.35 g