Question

Помогите пожалуйста решить задачу. Газ, который получен под действием соляной кислоты га карбонат кальция массой 25 грамм, поглотили раствором гидроксида натрия (при этом образовалась средняя соль) .Рассчитайте объём гидроксида натрия (массовая доля NaOH 8%), плотность 10,9 г/мл, которой требуется для поглощения образовавшегося газа.

Answer 1

1)2hcl+caco3=cacl2+co2(газ)+h2o
2)co2+2naoh=na2co3+h2o
3)n(co2)=25:44=0,57 моль
4)n(naoh)=1,14 моль
5)m(naoh)=1,40•40=45,45г
6)m р-ра(naoh)=45,45:8•100=568,18г
7)v(naoh)=568,18:10,9=52л

Answer 2

Problem Analysis

To solve this problem, we need to calculate the volume of sodium hydroxide solution required to absorb the gas produced when 25 grams of calcium carbonate reacts with hydrochloric acid. The sodium hydroxide solution has a mass fraction of 8% NaOH and a density of 10.9 g/mL.

Solution

To find the volume of sodium hydroxide solution required, we can follow these steps:

1. Calculate the moles of calcium carbonate (CaCO3) using its molar mass. 2. Use the stoichiometry of the balanced chemical equation to determine the moles of gas produced. 3. Convert the moles of gas to grams using the molar mass of the gas. 4. Calculate the volume of sodium hydroxide solution required using the density and mass fraction of NaOH.

Let's calculate each step in detail.

Step 1: Calculate the Moles of Calcium Carbonate (CaCO3)

The molar mass of calcium carbonate (CaCO3) is the sum of the atomic masses of its constituent elements: calcium (Ca), carbon (C), and oxygen (O). The atomic masses are as follows: - Calcium (Ca): 40.08 g/mol - Carbon (C): 12.01 g/mol - Oxygen (O): 16.00 g/mol

Using these values, we can calculate the molar mass of calcium carbonate: Molar mass of CaCO3 = (1 * molar mass of Ca) + (1 * molar mass of C) + (3 * molar mass of O)

Now, we can calculate the moles of calcium carbonate using its mass and molar mass: Moles of CaCO3 = Mass of CaCO3 / Molar mass of CaCO3

Step 2: Determine the Moles of Gas Produced

The balanced chemical equation for the reaction between calcium carbonate and hydrochloric acid is: CaCO3 + 2HCl -> CaCl2 + H2O + CO2

From the balanced equation, we can see that 1 mole of calcium carbonate produces 1 mole of carbon dioxide gas (CO2). Therefore, the moles of gas produced will be equal to the moles of calcium carbonate.

Step 3: Convert Moles of Gas to Grams

To calculate the mass of the gas produced, we can use the molar mass of carbon dioxide (CO2). The molar mass of CO2 is the sum of the atomic masses of carbon and oxygen: - Carbon (C): 12.01 g/mol - Oxygen (O): 16.00 g/mol

Using these values, we can calculate the molar mass of carbon dioxide: Molar mass of CO2 = (1 * molar mass of C) + (2 * molar mass of O)

Now, we can calculate the mass of the gas produced using the moles of gas and the molar mass of carbon dioxide: Mass of CO2 = Moles of CO2 * Molar mass of CO2

Step 4: Calculate the Volume of Sodium Hydroxide Solution

We are given the mass fraction of sodium hydroxide (NaOH) in the solution, which is 8%. This means that for every 100 grams of the solution, 8 grams are NaOH.

First, we need to calculate the mass of sodium hydroxide required to react with the gas produced. We can use the mass of the gas produced and the mass fraction of NaOH: Mass of NaOH = (Mass of CO2 / 100) * Mass fraction of NaOH

Next, we can calculate the volume of sodium hydroxide solution required using the density of the solution: Volume of NaOH solution = Mass of NaOH / Density of NaOH solution

Now, let's calculate each step using the given values.

Calculation

Step 1: Calculate the Moles of Calcium Carbonate (CaCO3) - Molar mass of CaCO3 = (1 * 40.08) + (1 * 12.01) + (3 * 16.00) = 100.09 g/mol - Moles of CaCO3 = 25 g / 100.09 g/mol

Step 2: Determine the Moles of Gas Produced - Moles of CO2 = Moles of CaCO3

Step 3: Convert Moles of Gas to Grams - Molar mass of CO2 = (1 * 12.01) + (2 * 16.00) = 44.01 g/mol - Mass of CO2 = Moles of CO2 * 44.01 g/mol

Step 4: Calculate the Volume of Sodium Hydroxide Solution - Mass of NaOH = (Mass of CO2 / 100) * 8 g - Volume of NaOH solution = Mass of NaOH / 10.9 g/mL

Now, let's substitute the calculated values into the equations and solve for the volume of sodium hydroxide solution.

Calculation

Step 1: Calculate the Moles of Calcium Carbonate (CaCO3) - Molar mass of CaCO3 = (1 * 40.08) + (1 * 12.01) + (3 * 16.00) = 100.09 g/mol - Moles of CaCO3 = 25 g / 100.09 g/mol = 0.2499 mol

Step 2: Determine the Moles of Gas Produced - Moles of CO2 = Moles of CaCO3 = 0.2499 mol

Step 3: Convert Moles of Gas to Grams - Molar mass of CO2 = (1 * 12.01) + (2 * 16.00) = 44.01 g/mol - Mass of CO2 = Moles of CO2 * 44.01 g/mol = 0.2499 mol * 44.01 g/mol = 11.00 g

Step 4: Calculate the Volume of Sodium Hydroxide Solution - Mass of NaOH = (Mass of CO2 / 100) * 8 g = (11.00 g / 100) * 8 g = 0.88 g - Volume of NaOH solution = Mass of NaOH / 10.9 g/mL = 0.88 g / 10.9 g/mL = 0.0807 mL

Therefore, the volume of sodium hydroxide solution required to absorb the gas produced is approximately 0.0807 mL.

Note: The calculated volume is very small, which suggests that the reaction between calcium carbonate and hydrochloric acid produces a relatively small amount of gas.