Question

Химия. 8-й класс. 96 грамм оксида меди (II) растворили в фосфорной кислоте (H3PO4). Определить массу образовавшейся соли. (Ответ записать с точностью до десятых).

Answer 1

Дано:

m(CuO)=96г

Найти:

m(H3PO4)=?

Объяснение:

Для начала уравняем реакцию:

3CuO+2H3PO4⇒Cu3(PO4)2+3H2O

n(CuO)=96:80=1,2

n(Cu3(PO4)2)=n(CuO):3=1,2:3=0,4

m(Cu3(PO4)2)=0,4*(192+62+128)=152,8

Ответ: 152,8 грамм

Answer 2

Calculating the Mass of the Formed Salt

To calculate the mass of the formed salt when 96 grams of copper (II) oxide is dissolved in phosphoric acid (H3PO4), we can use the chemical equation for the reaction between copper (II) oxide and phosphoric acid.

The balanced chemical equation for the reaction is as follows: CuO + 2H3PO4 → Cu(H2PO4)2 + H2O

From the balanced chemical equation, we can see that 1 mole of copper (II) oxide reacts with 2 moles of phosphoric acid to produce 1 mole of copper dihydrogen phosphate and water.

Step-by-Step Calculation

1. Calculate the moles of copper (II) oxide: - Given mass of copper (II) oxide = 96 grams - Molar mass of CuO = 63.55 g/mol (copper) + 15.999 g/mol (oxygen) = 79.55 g/mol - Moles of CuO = Given mass / Molar mass = 96 g / 79.55 g/mol = 1.206 moles

2. Calculate the moles of copper dihydrogen phosphate: - From the balanced chemical equation, 1 mole of CuO produces 1 mole of Cu(H2PO4)2 - Moles of Cu(H2PO4)2 = Moles of CuO = 1.206 moles

3. Calculate the mass of copper dihydrogen phosphate: - Molar mass of Cu(H2PO4)2 = 187.5 g/mol (copper) + 2*1.008 g/mol (hydrogen) + 2*30.974 g/mol (phosphorus) + 8*15.999 g/mol (oxygen) = 187.5 g/mol + 2.016 g/mol + 61.948 g/mol + 127.992 g/mol = 379.456 g/mol - Mass of Cu(H2PO4)2 = Moles of Cu(H2PO4)2 * Molar mass = 1.206 moles * 379.456 g/mol = 457.4 grams

Answer

The mass of the formed salt, copper dihydrogen phosphate, is 457.4 grams (to one decimal place).