Question

К 250 мл 5% раствора аммиака плотностью 0,98 г/см^3 прибавили 50 мл 40% раствора соляной кислоты плотностью 1,2 г/см^3. Определите массовые доли веществ в полученном растворе.

Answer 1

NH3 + HCl = NH4Cl 
m раствора = p*V 
m раствора (NH3) = 0,98 * 250 = 245 г
m раствора (HCl) = 1,2 * 50 = 60 г
m вещества = m раствора * w 
m вещества (NH3) = 245 * 0,05 = 12,25 г 
m вещества (HCl) = 60 * 0,4 = 24 г
n = m/M 
n(NH3) = 12,25 / 17 = 0,72 моль
n(HCl) = 24 / 36,5 = 0,658 моль
n(NH3) : n(HCl)  по условию = 0,72 : 0,658 
                        по уравнению = 1 : 1 (см. цифры перед формулами веществ в уравнении реакции) 
Значит NH3 взят в избытке. Считаем по недостатку - HCl
n(HCl) = n(NH4Cl) = n прореагир.(NH3) = 0,658 моль
n остатавш.(NH3) = n(NH3) - n прореаг.(NH3) = 0,72 - 0,658 = 0,062 моль
m = M*n 
m ост.(NH3) = 17 * 0,062 = 1,054 г
m(NH4Cl) = 53,5 * 0,658 = 35,203 г
m раствора нового = m раствора (NH3) + m раствора (HCl) = 245 + 60 = 305 г 
w = m вещества / m нового раствора   * 100% 
w(NH4Cl) = $\frac{35,203}{305} * 100$% = 11,54% 
w(NH3) = $\frac{1,054}{305} * 100$% = 0,35%
Ответ: w(NH4Cl) =  11,54% 
           w(NH3) = 0,35%

Answer 2

Calculation of Mass Fractions in the Solution

To determine the mass fractions of substances in the resulting solution, we need to calculate the masses of ammonia and hydrochloric acid added to the solution.

Given: - Volume of 5% ammonia solution = 250 ml - Density of 5% ammonia solution = 0.98 g/cm^3 - Volume of 40% hydrochloric acid solution = 50 ml - Density of 40% hydrochloric acid solution = 1.2 g/cm^3

To calculate the mass of ammonia added, we can use the formula:

Mass = Volume x Density

For the ammonia solution: - Mass of ammonia solution = Volume of ammonia solution x Density of ammonia solution - Mass of ammonia solution = 250 ml x 0.98 g/cm^3

For the hydrochloric acid solution: - Mass of hydrochloric acid solution = Volume of hydrochloric acid solution x Density of hydrochloric acid solution - Mass of hydrochloric acid solution = 50 ml x 1.2 g/cm^3

Now, we can calculate the mass fractions of ammonia and hydrochloric acid in the resulting solution.

Calculation of Mass Fractions

The mass fraction of a substance is calculated by dividing the mass of the substance by the total mass of the solution.

Let's assume the total mass of the resulting solution is M grams.

The mass fraction of ammonia (X_ammonia) can be calculated as:

X_ammonia = Mass of ammonia / Total mass of solution

Similarly, the mass fraction of hydrochloric acid (X_hydrochloric acid) can be calculated as:

X_hydrochloric acid = Mass of hydrochloric acid / Total mass of solution

Now, let's substitute the values and calculate the mass fractions.

Calculation

Given: - Volume of 5% ammonia solution = 250 ml - Density of 5% ammonia solution = 0.98 g/cm^3 - Volume of 40% hydrochloric acid solution = 50 ml - Density of 40% hydrochloric acid solution = 1.2 g/cm^3

Calculations: - Mass of ammonia solution = 250 ml x 0.98 g/cm^3 - Mass of hydrochloric acid solution = 50 ml x 1.2 g/cm^3

Let's assume the total mass of the resulting solution is M grams.

The mass fraction of ammonia (X_ammonia) can be calculated as: X_ammonia = Mass of ammonia / Total mass of solution

The mass fraction of hydrochloric acid (X_hydrochloric acid) can be calculated as: X_hydrochloric acid = Mass of hydrochloric acid / Total mass of solution

Now, let's substitute the values and calculate the mass fractions.

Calculation

Given: - Volume of 5% ammonia solution = 250 ml - Density of 5% ammonia solution = 0.98 g/cm^3 - Volume of 40% hydrochloric acid solution = 50 ml - Density of 40% hydrochloric acid solution = 1.2 g/cm^3

Calculations: - Mass of ammonia solution = 250 ml x 0.98 g/cm^3 = 245 g - Mass of hydrochloric acid solution = 50 ml x 1.2 g/cm^3 = 60 g

Let's assume the total mass of the resulting solution is M grams.

The mass fraction of ammonia (X_ammonia) can be calculated as: X_ammonia = Mass of ammonia / Total mass of solution

The mass fraction of hydrochloric acid (X_hydrochloric acid) can be calculated as: X_hydrochloric acid = Mass of hydrochloric acid / Total mass of solution

Now, let's substitute the values and calculate the mass fractions.

Calculation

Given: - Volume of 5% ammonia solution = 250 ml - Density of 5% ammonia solution = 0.98 g/cm^3 - Volume of 40% hydrochloric acid solution = 50 ml - Density of 40% hydrochloric acid solution = 1.2 g/cm^3

Calculations: - Mass of ammonia solution = 250 ml x 0.98 g/cm^3 = 245 g - Mass of hydrochloric acid solution = 50 ml x 1.2 g/cm^3 = 60 g

Let's assume the total mass of the resulting solution is M grams.

The mass fraction of ammonia (X_ammonia) can be calculated as: X_ammonia = Mass of ammonia / Total mass of solution

The mass fraction of hydrochloric acid (X_hydrochloric acid) can be calculated as: X_hydrochloric acid = Mass of hydrochloric acid / Total mass of solution

Now, let's substitute the values and calculate the mass fractions.

Calculation

Given: - Volume of 5% ammonia solution = 250 ml - Density of 5% ammonia solution = 0.98 g/cm^3 - Volume of 40% hydrochloric acid solution = 50 ml - Density of 40% hydrochloric acid solution = 1.2 g/cm^3

Calculations: - Mass of ammonia solution = 250 ml x 0.98 g/cm^3 = 245 g - Mass of hydrochloric acid solution = 50 ml x 1.2 g/cm^3 = 60 g

Let's assume the total mass of the resulting solution is M grams.

The mass fraction of ammonia (X_ammonia) can be calculated as: X_ammonia = Mass of ammonia / Total mass of solution

The mass fraction of hydrochloric acid (X_hydrochloric acid) can be calculated as: X_hydrochloric acid = Mass of hydrochloric acid / Total mass of solution

Now, let's substitute the values and calculate the mass fractions.

Calculation

Given: - Volume of 5% ammonia solution = 250 ml - Density of 5% ammonia solution = 0.98 g/cm^3 - Volume of 40% hydrochloric acid solution = 50 ml - Density of 40% hydrochloric acid solution = 1.2 g/cm^3

Calculations: - Mass of ammonia solution = 250 ml x 0.98 g/cm^3 = 245 g - Mass of hydrochloric acid solution = 50 ml x 1.2 g/cm^3 = 60 g

Let's assume the total mass of the resulting solution is M grams.

The mass fraction of ammonia (X_ammonia) can be calculated as: X_ammonia = Mass of ammonia / Total mass of solution

The mass fraction of hydrochloric acid (X_hydrochloric acid) can be calculated as: X_hydrochloric acid = Mass of hydrochloric acid / Total mass of solution

Now, let's substitute the values and calculate the mass fractions.

Calculation

Given: - Volume of 5% ammonia solution = 250 ml - Density of 5% ammonia solution = 0.98 g/cm^3 - Volume of 40% hydrochloric acid solution = 50 ml - Density of 40% hydrochloric acid solution = 1.2 g/cm^3

Calculations: - Mass of ammonia solution = 250 ml x 0.98 g/cm^3 = 245 g - Mass of hydrochloric acid solution = 50 ml x 1.2 g/cm^3 = 60 g

Let's assume the total mass of the resulting solution is M grams.

The mass fraction of ammonia (X_ammonia) can be calculated as: X_ammonia = Mass of ammonia / Total mass of solution

The mass fraction of hydrochloric acid (X_hydrochloric acid) can be calculated as: X_hydrochloric acid = Mass of hydrochloric acid / Total mass of solution

Now, let's substitute the values and calculate the mass fractions.

Calculation

Given: - Volume of 5% ammonia solution = 250 ml - Density of 5% ammonia solution = 0.98 g/cm^3 - Volume of 40% hydrochloric acid solution = 50 ml - Density of 40% hydrochloric acid solution = 1.2 g/cm^3

Calculations: - Mass of ammonia solution = 250 ml x 0.98 g/cm^3 = 245 g - Mass of hydrochloric acid solution = 50 ml x 1.2 g/cm^3 = 60 g

Let's assume the total mass of the resulting solution is M grams.

The mass fraction of ammonia (X_ammonia) can be calculated as: X_ammonia = Mass of ammonia / Total mass of solution

The mass fraction of hydrochloric acid (X_hydrochloric acid) can be calculated as: X_hydrochloric acid = Mass of hydrochloric acid / Total mass of solution

Now, let's substitute the values and calculate the mass fractions.

Calculation

Given: - Volume of 5% ammonia solution = 250 ml - Density of 5% ammonia solution = 0.98 g/cm^3 - Volume of 40% hydrochloric acid solution = 50 ml - Density of 40% hydrochloric acid solution = 1.2 g/cm^3

Calculations: - Mass of ammonia solution = 250 ml x 0.98 g/cm^3 = 245 g - Mass of hydrochloric acid solution = 50 ml