Question

На гидрооксид натрия подействовали раствором содержащим 252 г соляной кислоты. Вычислите массу полученной соли, если практический выход составляет 90% от теоретического

Answer 1

1)Напишем уравнение реакции:

           252 г                х г

NaOH+HCl==========>NaCl + H2O  

        M=36,5г/моль     58,5г/моль

        m= 36,5г             58,5 г

Составляем пропорцию: 252/36,5=x/58,5

Выводим: x=252*58,5/36,5 =404 г(примерно)

2)Это мы узнали сколько на теории должно было выйти.Теперь узнаем сколько вышло на практике,так как на практике всегда выходит меньше(всякие погрешности во время опыта)

Формула: w(выхода)=m(практическая)*100%/m(теоритическая)

Выводим: m(практическая)=w*m(теоритическая)/100% 

m(практ.)=90% * 404г/100% =363,6 г

Ответ:363,6 г. 

Answer 2

Calculation of the Mass of the Obtained Salt

To calculate the mass of the obtained salt, we need to consider the reaction between sodium hydroxide (NaOH) and hydrochloric acid (HCl). The balanced equation for this reaction is:

NaOH + HCl -> NaCl + H2O

According to the question, 252 g of hydrochloric acid (HCl) was reacted with sodium hydroxide (NaOH). The practical yield of the reaction is given as 90% of the theoretical yield.

To calculate the mass of the obtained salt (NaCl), we can follow these steps:

1. Calculate the molar mass of hydrochloric acid (HCl): - The molar mass of hydrogen (H) is approximately 1 g/mol. - The molar mass of chlorine (Cl) is approximately 35.5 g/mol. - Therefore, the molar mass of HCl is approximately 1 g/mol + 35.5 g/mol = 36.5 g/mol.

2. Calculate the number of moles of HCl: - Divide the given mass of HCl (252 g) by its molar mass (36.5 g/mol): 252 g / 36.5 g/mol ≈ 6.904 moles of HCl.

3. Since the reaction is 1:1 between NaOH and HCl, the number of moles of NaCl formed will be the same as the number of moles of HCl.

4. Calculate the theoretical yield of NaCl: - The theoretical yield is the number of moles of NaCl formed. - In this case, the theoretical yield is also approximately 6.904 moles.

5. Calculate the mass of the obtained salt (NaCl): - Multiply the theoretical yield (6.904 moles) by the molar mass of NaCl (approximately 58.5 g/mol): 6.904 moles * 58.5 g/mol ≈ 403.476 g.

6. Calculate the mass of the obtained salt, considering the practical yield: - The practical yield is given as 90% of the theoretical yield. - Multiply the theoretical yield (403.476 g) by 90% (0.9): 403.476 g * 0.9 ≈ 363.1284 g.

Therefore, the mass of the obtained salt (NaCl) is approximately 363.1284 grams.