Question

К 250 г раствора азотом кислоты с массовой долей 5% добавили ещё 50г азотом кислоты. Какой стала массовая доля Hno3 в растворе

Answer 1

M(HNO3)1 = mp-pa1*W1 = 250*0,05 = 12,5 г
m(HNO3)2 = 12,5 + 50 = 62,5 г
mp-pa2 = mp-pa1 + 50 = 250+50 = 300 г
W(HNO3)2 = m(HNO3)2/mp-pa2 = 0,208 или 20,8 %

Answer 2

Calculation of the New Mass Fraction of HNO3 in the Solution

To calculate the new mass fraction of HNO3 in the solution, we need to consider the initial mass of the solution and the mass of the additional nitric acid added.

Given: - Initial mass of the solution = 250 g - Mass fraction of HNO3 in the initial solution = 5% - Mass of additional nitric acid added = 50 g

To find the new mass fraction of HNO3, we can follow these steps:

1. Calculate the initial mass of HNO3 in the solution: - Initial mass of HNO3 = Initial mass of the solution * Mass fraction of HNO3 - Initial mass of HNO3 = 250 g * 5% = 12.5 g

2. Calculate the total mass of the solution after adding the additional nitric acid: - Total mass of the solution = Initial mass of the solution + Mass of additional nitric acid - Total mass of the solution = 250 g + 50 g = 300 g

3. Calculate the new mass fraction of HNO3 in the solution: - New mass fraction of HNO3 = (Initial mass of HNO3 + Mass of additional nitric acid) / Total mass of the solution - New mass fraction of HNO3 = (12.5 g + 50 g) / 300 g

Let's calculate the new mass fraction of HNO3 in the solution:

New mass fraction of HNO3 = (12.5 g + 50 g) / 300 g = 62.5 g / 300 g = 20.83%

Therefore, the new mass fraction of HNO3 in the solution is approximately 20.83%.

Please note that the calculation assumes that the volumes of the solutions are additive and that there is no significant change in the density of the solution upon mixing.