In 400 mg of a 25% potassium hydroxide solution, 45% carbon dioxide was dissolved. Calculate the mass of the salt formed.
July 28, 2021 | education|
The problem for the excess and lack of reagents.
Let’s find the amount of the substance KOH and CO2:
m (KOH) = 0.4 x 0.25 = 0.1 g;
n (KOH) = 0.1 / 56 = 0.0018 mol;
Let’s find the mass of carbon dioxide. It is known that after dissolution, its mass fraction (excluding the reaction) was 45%. Let m be the mass of dissolved CO2, then:
m (CO2) / (m (CO2) + 0.4) = 0.45;
m (CO2) = 0.28 g;
n (CO2) = 0.28 / 44 = 0.0063 mol;
Carbon dioxide in excess, the reaction of formation of potassium bicarbonate will proceed:
KOH + CO2 = KHCO3
n (salt) = n (KOH) = 0.0018 mol;
m (salt) = 0.0018 × 100 = 0.18 g
Answer: m (salt) = 0.18 g.
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.