Question

Задача 1. 300 г 15 процентного раствора Na2CO2 прилили избыток раствора HCl .вычисли объём выделившегося Газа. Задача 2: 2 моль осадка получено при взаимодействии ZnCl2 и Na2S. какая масса сульфида натрия прореагировала?

Answer 1

1. Na2CO3+2HCl=2NaCl+H2O+CO2

m(Na2CO3)=300*0,15=45(г)

n(Na2CO3)=45/106=0,425(моль)

V(CO2)=0,425*22,4=9,52(л)

Ответ: 9,52 л

2. ZnCl2+Na2S=ZnS+2NaCl

n(ZnS)=2 моль

n(Na2S)=n(ZnS)=2 моль

m(Na2S)=n(Na2S)*M(Na2S)=2 моль*78 г/моль = 156(г)

Ответ: 156 г

Answer 2

Task 1: Calculating the Volume of Gas Evolved

To calculate the volume of gas evolved when an excess of hydrochloric acid (HCl) reacts with 300 g of a 15% solution of sodium carbonate (Na2CO3), we need to consider the balanced chemical equation for the reaction.

The balanced chemical equation for the reaction between sodium carbonate and hydrochloric acid is:

Na2CO3 + 2HCl → 2NaCl + H2O + CO2

From the balanced equation, we can see that 1 mole of sodium carbonate reacts with 2 moles of hydrochloric acid to produce 1 mole of carbon dioxide gas.

To calculate the volume of gas evolved, we need to follow these steps:

1. Convert the mass of sodium carbonate to moles. 2. Use the mole ratio from the balanced equation to determine the moles of carbon dioxide gas produced. 3. Convert the moles of carbon dioxide gas to volume using the ideal gas law.

Let's calculate the volume of gas evolved step by step.

Step 1: Convert the mass of sodium carbonate to moles.

The molar mass of sodium carbonate (Na2CO3) can be calculated by adding the atomic masses of its constituent elements:

Na: 22.99 g/mol C: 12.01 g/mol O: 16.00 g/mol

Molar mass of Na2CO3 = (2 * 22.99) + 12.01 + (3 * 16.00) = 105.99 g/mol

Given that the mass of the 15% solution of sodium carbonate is 300 g, we can calculate the number of moles using the formula:

Number of moles = Mass / Molar mass

Number of moles of Na2CO3 = 300 g / 105.99 g/mol

[[1]]

Step 2: Use the mole ratio from the balanced equation to determine the moles of carbon dioxide gas produced.

From the balanced equation, we know that 1 mole of sodium carbonate reacts with 2 moles of hydrochloric acid to produce 1 mole of carbon dioxide gas.

Therefore, the number of moles of carbon dioxide gas produced is equal to the number of moles of sodium carbonate.

Number of moles of CO2 = Number of moles of Na2CO3

[[1]]

Step 3: Convert the moles of carbon dioxide gas to volume using the ideal gas law.

The ideal gas law equation is given by:

PV = nRT

Where: P = pressure of the gas (in atm) V = volume of the gas (in liters) n = number of moles of the gas R = ideal gas constant (0.0821 L·atm/(mol·K)) T = temperature of the gas (in Kelvin)

Since the pressure, temperature, and number of moles are not provided in the question, we cannot calculate the exact volume of gas evolved. To calculate the volume, we need additional information.

Please provide the pressure, temperature, or any other relevant information to proceed with the calculation.

Task 2: Calculating the Mass of Sodium Sulfide Reacted

To calculate the mass of sodium sulfide (Na2S) that reacted when 2 moles of zinc chloride (ZnCl2) react, we need to consider the balanced chemical equation for the reaction.

The balanced chemical equation for the reaction between zinc chloride and sodium sulfide is:

ZnCl2 + Na2S → ZnS + 2NaCl

From the balanced equation, we can see that 1 mole of zinc chloride reacts with 1 mole of sodium sulfide to produce 1 mole of zinc sulfide.

To calculate the mass of sodium sulfide reacted, we need to follow these steps:

1. Convert the number of moles of zinc chloride to moles of sodium sulfide using the mole ratio from the balanced equation. 2. Convert the moles of sodium sulfide to mass using the molar mass of sodium sulfide.

Let's calculate the mass of sodium sulfide reacted step by step.

Step 1: Convert the number of moles of zinc chloride to moles of sodium sulfide using the mole ratio from the balanced equation.

From the balanced equation, we know that 1 mole of zinc chloride reacts with 1 mole of sodium sulfide.

Therefore, the number of moles of sodium sulfide reacted is equal to the number of moles of zinc chloride.

Number of moles of Na2S = Number of moles of ZnCl2 = 2 moles

[[2]]

Step 2: Convert the moles of sodium sulfide to mass using the molar mass of sodium sulfide.

The molar mass of sodium sulfide (Na2S) can be calculated by adding the atomic masses of its constituent elements:

Na: 22.99 g/mol S: 32.07 g/mol

Molar mass of Na2S = (2 * 22.99) + 32.07 = 74.05 g/mol

To calculate the mass of sodium sulfide reacted, we can use the formula:

Mass = Number of moles * Molar mass

Mass of Na2S = 2 moles * 74.05 g/mol

[[2]]

Please note that the exact mass of sodium sulfide reacted cannot be calculated without knowing the number of moles of zinc chloride used in the reaction.

If you have any additional information, such as the number of moles of zinc chloride, please provide it so that we can calculate the mass of sodium sulfide reacted accurately.