Question

200 г смеси карбоната и гидрокарбоната натрия нагревали до постоянной массы.Масса твердого остатка составила 138 г Опредеоите состав исходной смеси в массовых процентах

Answer 1

2NaHCO3 = Na2CO3 + H2O + CO2

Пусть х - масса карбоната натрия, тогда масса гидрокарбоната = 200 - х 

 138 = x + ((200 - x) * 106 / 168)

138 = 0.37x + 126

0.37x = 12

x= 32.4

 32.4 : 200 * 100% = 16.2% (Na2CO3)

Answer 2

2NaHCO3 = Na2CO3 + H2O + CO2

Пусть х - масса карбоната натрия, тогда масса гидрокарбоната = 200 - х 

 

138 = x + ((200 - x) * 106 / 168)

138 = 0.37x + 126

0.37x = 12

x= 32.4

 

32.4 : 200 * 100% = 16.2% (Na2CO3) 

Answer 3

Calculation of the Composition of the Mixture

To determine the composition of the initial mixture in mass percentages, we need to analyze the information provided.

According to the given information, 200 g of a mixture of sodium carbonate and sodium hydrogencarbonate was heated until a constant mass was obtained. The mass of the solid residue was found to be 138 g.

To calculate the composition of the mixture, we need to determine the mass of each component present in the mixture.

Let's assume: - Mass of sodium carbonate in the mixture = x grams - Mass of sodium hydrogencarbonate in the mixture = y grams

Since the total mass of the mixture is 200 g, we can write the equation: x + y = 200 ---(Equation 1)

Given that the mass of the solid residue (after heating) is 138 g, we can write another equation: x + y = 138 ---(Equation 2)

Solving these two equations simultaneously will give us the values of x and y, which represent the masses of sodium carbonate and sodium hydrogencarbonate, respectively.

Subtracting Equation 2 from Equation 1, we get: (x + y) - (x + y) = 200 - 138 Simplifying, we find: 0 = 62

This implies that the two equations are contradictory, and there is no solution that satisfies both equations simultaneously. Therefore, the given information is inconsistent, and we cannot determine the composition of the initial mixture in mass percentages based on the provided data.

Please provide additional information or clarify the given data to proceed with the calculation.