Question

Какая масса гидроксида кальция образуется в результате действия воды на 280г кальций оксида?

Answer 1

Дано
m(CaO)=280 g
-------------------
m(Ca(OH)2-?
  280                   X
CaO+H2O-->Ca(OH)2  M(CaO)=56 g/mol , M(Ca(OH)2)=74 g/mol
  56                   74

280 / 56 = X / 74 
X=370 g
ответ 370 г

Answer 2

Calculating the mass of calcium hydroxide formed

The question asks us to calculate the mass of calcium hydroxide (Ca(OH)2) formed when 280g of calcium oxide (CaO) reacts with water.

The key reaction taking place is: CaO + H2O → Ca(OH)2

The steps to solve this are: 1. Write the balanced chemical equation for the reaction 2. Determine the mole ratios between reactants and products using the balanced equation 3. Convert the given mass of calcium oxide to moles using its molar mass 4. Use the mole ratio and calculated moles of calcium oxide to determine the moles of calcium hydroxide formed 5. Convert the moles of calcium hydroxide to mass using its molar mass

Working through the steps: 1. The balanced equation is: CaO + H2O → Ca(OH)2 2. The mole ratio from the equation is: 1 mol CaO : 1 mol Ca(OH)2 3. Mass of CaO given = 280g Molar mass of CaO = 56.08g/mol Moles of CaO = Mass / Molar mass = 280g / 56.08g/mol = 5 mol 4. Moles of Ca(OH)2 from mole ratio = Moles of CaO = 5 mol 5. Molar mass of Ca(OH)2 = 74.09g/mol Mass of Ca(OH)2 = Moles x Molar mass = 5 mol x 74.09g/mol = 370.45g

Therefore, the mass of calcium hydroxide formed is 370.45g.