Question

Pure sodium metal reacts violently with water according to the equation below

Na + H2O - NaO + H2
17 mol
If 0.75 mol of Na is placed in 500 g of
H,O how many moles of hydrogen
gas will be produced?
0.75 mol
28 mol
1.5 mol

Answer 1

0.75 mol

Step-by-step explanation:

Given data:

Number of moles of Na = 0.75 mol

Mass of water = 500 g

Moles of hydrogen gas produced = ?

Solution:

Chemical equation:

Na + H₂O → NaO + H₂

Number of moles of water:

Number of moles = mass/molar mass

Number of moles = 500 g/ 18 g/mol

Number of moles = 27.8 mol

now we will compare the moles of hydrogen gas with both reactant.

Na : H₂

1 : 1

0.75 : 0.75

H₂O : H₂

1 : 1

27.8 : 27.8

sodium will act as limiting reactant it produced small number of moles of hydrogen gas as compared to water.

Thus, number of moles of hydrogen gas are 0.75 mol.