What is the mass of sodium carbonate obtained by passing carbon monoxide (IV) with a mass of 22 g through a solution
What is the mass of sodium carbonate obtained by passing carbon monoxide (IV) with a mass of 22 g through a solution with a mass of 20 g with a mass fraction of sodium hydroxide of 25%?
Given:
m (CO2) = 22 g
m (NaOH) = 20 g
w% (NaOH) = 25%
To find:
m (Na2CO3) -?
Decision:
1) We compose the reaction equation according to the condition of the problem:
2NaOH + CO2 = Na2CO3 + H2;
2) Find the mass of alkali in the solution:
m (NaOH) = 20 g * 0.25 = 5 g;
3) Find the amount of carbon monoxide and sodium hydroxide:
n (CO2) = m: M = 22 g: 44 g / mol = 0.5 mol
n (NaOH) = m: M = 5 g: 40 g / mol = 0.125 mol
We start from a lower value to get more accurate calculations. We work with NaOH:
4) We compose logical equality:
if 2 mol NaOH gives 1 mol Na2CO3,
then 0.125 mol NaOH will give x mol Na2CO3,
then x = 0.0625 mol.
5) Find the mass of sodium carbonate formed as a result of the reaction:
m (Na2CO3) = n * M = 0.0625 mol * 106 g / mol = 6.625 g;
Answer: m (Na2CO3) = 6.625 g.