Question

А 630 мл 20% раствора азотной кислоты плотностью 1.12 г/мл добавили 126 г этой кислоты найдите массовую долю кислоты в полученном растворе

Answer 1

M раствора = p * V 
m раствора (1) = 1,12 * 630 = 705,6 г 
m вещества = m раствора * w 
m (NHO3) (вещества) (1) = 705,6 * 0,2 = 141,12 г 
w = $\frac{m (veshestva)(2)}{m (rastvora)(2)}$ * 100 % 
( m (veshectva) - m вещества 
m (rastvora) - m раствора ) 
m (HNO3) (вещества) (2) = m (HNO3) (в-ва) (1) + m (HNO3) добавлен. = 141,12 + 126 = 267,12 г 
m раствора (2) = m раствора (1) + m (HNO3) добавлен. = 705,6 + 126 = 831,6 г 
w (HNO3) = $\frac{267,12}{831,6}$ * 100% = 32,12 % 
Ответ: 32,12% 

Answer 2

Calculation of Mass Fraction of Nitric Acid in the Solution

To find the mass fraction of nitric acid in the solution, we need to calculate the mass of nitric acid in the solution and divide it by the total mass of the solution.

Given information: - Volume of the solution: 630 mL - Concentration of the solution: 20% - Density of the solution: 1.12 g/mL - Mass of nitric acid added: 126 g

First, let's calculate the mass of the solution using the given volume and density: Mass of the solution = Volume of the solution × Density of the solution Mass of the solution = 630 mL × 1.12 g/mL

To calculate the mass of nitric acid in the solution, we need to consider the concentration of the solution. The concentration of 20% means that 20 g of nitric acid is present in 100 g of the solution. We can use this information to calculate the mass of nitric acid in the solution: Mass of nitric acid in the solution = Mass of the solution × Concentration of nitric acid Mass of nitric acid in the solution = (Mass of the solution × 20%) / 100

Finally, we can calculate the mass fraction of nitric acid in the solution: Mass fraction of nitric acid = Mass of nitric acid in the solution / Mass of the solution

Let's calculate the values step by step:

1. Calculate the mass of the solution: - Volume of the solution = 630 mL - Density of the solution = 1.12 g/mL - Mass of the solution = 630 mL × 1.12 g/mL

2. Calculate the mass of nitric acid in the solution: - Mass of the solution (from step 1) = calculated value - Concentration of nitric acid = 20% - Mass of nitric acid in the solution = (Mass of the solution × 20%) / 100

3. Calculate the mass fraction of nitric acid in the solution: - Mass of nitric acid in the solution (from step 2) = calculated value - Mass fraction of nitric acid = Mass of nitric acid in the solution / Mass of the solution

Let's calculate the values:

1. Calculate the mass of the solution: - Volume of the solution = 630 mL - Density of the solution = 1.12 g/mL - Mass of the solution = 630 mL × 1.12 g/mL = 705.6 g

2. Calculate the mass of nitric acid in the solution: - Mass of the solution = 705.6 g - Concentration of nitric acid = 20% - Mass of nitric acid in the solution = (705.6 g × 20%) / 100 = 141.12 g

3. Calculate the mass fraction of nitric acid in the solution: - Mass of nitric acid in the solution = 141.12 g - Mass fraction of nitric acid = 141.12 g / 705.6 g

Therefore, the mass fraction of nitric acid in the obtained solution is approximately 0.20 or 20%.

Please note that the calculations provided are based on the given information and assumptions.