1mol ------------ 3×6,02×10²³ oxygen atoms
x ------------ 2,55×10²⁴
x = 2,5×10²⁴ × 1mol / 3×6,02×10²³ ≈ 0,138*10 mol = 1,38mol
Molarity=moles/litre
molarity=0.5/0.1
molarity=5.00m
Answer:
15.438g H2O
Explanation:
First you need to find the reaction equation:
2H2O+2Na=2NaOH + H2
Hydrogen is a diatomic molecule so it will have a subscript of 2 on the right hand side. From there we can balance the reaction.
Then we can use stoichiometry:
34.2g NaOH * (1 mol NaOH/39.908g NaOH) * (2 mol H2O/2 mol NaOH) * (18.015g H2O/1 mol H20) = 15.438g H2O
It is important that when you use stoichiometry that all your units cancel out until you only have the unit you want.
