Question

При растворении некоторого количества кальция карбоната в хлоридной кислоте выделился углекислый газ, пропущенный через раствор КОН. В результате реакции образовалось 40 г калия карбоната. Какая масса CaCO3 была растворена в кислоте?​

Answer 1

Ответ:

х 0,285

СаCO3 +2HCl=CaCl2 +H2O +CO2

100 1моль

х=28,5гр

х 40

2KOH + CO2= K2CO3 H2O х=0,285

1моль 138

Answer 2

Calculation of the Mass of CaCO3 Dissolved in the Acid

To determine the mass of CaCO3 that was dissolved in the hydrochloric acid, we can use the information provided in the question.

According to the question, when a certain amount of calcium carbonate (CaCO3) was dissolved in hydrochloric acid (HCl), carbon dioxide gas (CO2) was released. This carbon dioxide gas was then passed through a solution of potassium hydroxide (KOH), resulting in the formation of 40 g of potassium carbonate (K2CO3).

To find the mass of CaCO3 dissolved in the acid, we need to calculate the molar mass of K2CO3 and then use stoichiometry to determine the mass of CaCO3.

Calculation Steps:

1. Calculate the molar mass of K2CO3: - The molar mass of K2CO3 can be calculated by adding up the atomic masses of its constituent elements. - The atomic masses of potassium (K), carbon (C), and oxygen (O) are approximately 39.1 g/mol, 12.01 g/mol, and 16.00 g/mol, respectively. - Since there are two potassium atoms in K2CO3, we multiply the atomic mass of potassium by 2. - The molar mass of K2CO3 is therefore: (2 * 39.1 g/mol) + 12.01 g/mol + (3 * 16.00 g/mol) = 138.21 g/mol.

2. Use stoichiometry to find the mass of CaCO3: - The balanced chemical equation for the reaction between CaCO3 and HCl is: CaCO3 + 2HCl -> CaCl2 + H2O + CO2 - From the balanced equation, we can see that 1 mole of CaCO3 reacts with 2 moles of HCl to produce 1 mole of CO2. - Since the molar mass of CO2 is approximately 44.01 g/mol, we can calculate the moles of CO2 produced by dividing the mass of K2CO3 (40 g) by the molar mass of K2CO3 (138.21 g/mol): Moles of CO2 = 40 g / 138.21 g/mol = 0.289 mol. - Since 1 mole of CaCO3 produces 1 mole of CO2, the moles of CaCO3 dissolved in the acid is also 0.289 mol. - Finally, we can calculate the mass of CaCO3 by multiplying the moles of CaCO3 by its molar mass (100.09 g/mol): Mass of CaCO3 = 0.289 mol * 100.09 g/mol = 28.92 g.

Therefore, the mass of CaCO3 that was dissolved in the hydrochloric acid is approximately 28.92 grams.