Question

126 г 5%-ного раствора HNO3 реагируют с Cu(OH)2. Необходимо найти m(соли). Пожалуйста, напишите полное решение!

Answer 1

Дано:

m(HNO3)=126г.

Сu(OH)2

m(Сu(OH)2)=?

Решение

2HNO3 + Cu(OH)2 = Cu(NO3)2 + 2H20

ню(HNO3)=126г./63г/моль=2моль

пропорция:

2 моль/2 моль=х моль/1 моль

х моль= (2*1)/2= 1 моль

M(Cu(NO3)2)=64+14*2+16*3*2=64+28+96=188 г/моль

m(Cu(NO3)2)= 1моль*188 г/моль=188г

Ответ:188г.

Answer 2

Problem Analysis

We are given that 126 g of a 5% solution of HNO3 reacts with Cu(OH)2. We need to find the mass of the salt (Cu(NO3)2) formed.

Solution

To solve this problem, we need to follow these steps:

1. Calculate the number of moles of HNO3 in the solution. 2. Use the balanced chemical equation to determine the stoichiometry between HNO3 and Cu(NO3)2. 3. Calculate the number of moles of Cu(NO3)2 formed. 4. Convert the moles of Cu(NO3)2 to grams.

Let's calculate each step in detail.

Step 1: Calculate the number of moles of HNO3

To calculate the number of moles of HNO3, we need to use the formula:

moles = mass / molar mass

The molar mass of HNO3 is 63.01 g/mol Since we have a 5% solution, we can calculate the mass of HNO3 in the solution:

mass of HNO3 = 5% * 126 g = 6.3 g

Now, we can calculate the number of moles of HNO3:

moles of HNO3 = 6.3 g / 63.01 g/mol = 0.1 mol

Step 2: Determine the stoichiometry between HNO3 and Cu(NO3)2

The balanced chemical equation for the reaction between HNO3 and Cu(OH)2 is:

2 HNO3 + Cu(OH)2 → Cu(NO3)2 + 2 H2O

From the balanced equation, we can see that 2 moles of HNO3 react with 1 mole of Cu(NO3)2.

Step 3: Calculate the number of moles of Cu(NO3)2 formed

Since we know that 2 moles of HNO3 react with 1 mole of Cu(NO3)2, we can use the stoichiometry to calculate the number of moles of Cu(NO3)2 formed:

moles of Cu(NO3)2 = (moles of HNO3) / 2 = 0.1 mol / 2 = 0.05 mol

Step 4: Convert the moles of Cu(NO3)2 to grams

To convert the moles of Cu(NO3)2 to grams, we need to use the formula:

mass = moles * molar mass

The molar mass of Cu(NO3)2 is 187.56 g/mol Now, we can calculate the mass of Cu(NO3)2 formed:

mass of Cu(NO3)2 = 0.05 mol * 187.56 g/mol = 9.378 g

Therefore, the mass of the salt (Cu(NO3)2) formed is 9.378 grams.

Answer

The mass of the salt (Cu(NO3)2) formed is 9.378 grams.