Question

Помогите пожалуйста! 1) Рассчитайте относительные молекулярные массы веществ, формулы которых CaO, CuCl2. Вычислите массовую долю элементов в первом соединении.

Answer 1

Mr(CaO) = 40 + 16 = 56 (Са = 40, О = 16)
Mr(CuCl2) = 64 + 35 · 2 = 134 (Cu = 64, Cl = 35)
w(Ca) = 40/56 = 0,714, или 71,4%
w(O) = 16/56 = 0,285, или 28,5%

Знаешь, тема довольно легкая, берешь атомную массу данного элемента, складываешь с атомной массой другого и ответ готов. Если присутствует цифра "2", или любая другая, то просто умнажаешь элемент стоящий перед данной цифрой и получаешь правильный ответ :)

Answer 2

Calculating Relative Molecular Masses and Elemental Composition

To calculate the relative molecular masses of the substances CaO and CuCl2, we can use the atomic masses of the elements involved.

The relative molecular mass of CaO (calcium oxide) can be calculated as follows: - The atomic mass of calcium (Ca) is 40.08 u. - The atomic mass of oxygen (O) is 16.00 u. - Therefore, the relative molecular mass of CaO is 40.08 + 16.00 = 56.08 u.

The relative molecular mass of CuCl2 (copper(II) chloride) can be calculated as follows: - The atomic mass of copper (Cu) is 63.55 u. - The atomic mass of chlorine (Cl) is 35.45 u. - Therefore, the relative molecular mass of CuCl2 is 63.55 + (35.45 * 2) = 134.45 u.

Calculating Mass Percentage of Elements in CaO

To calculate the mass percentage of elements in CaO, we can use the following steps: 1. Calculate the molar mass of CaO, which we already found to be 56.08 u. 2. Determine the mass of each element in CaO: - Mass of Ca = 40.08 u - Mass of O = 16.00 u 3. Calculate the mass percentage of each element: - Mass percentage of Ca = (40.08 / 56.08) * 100% = 71.43% - Mass percentage of O = (16.00 / 56.08) * 100% = 28.57%

Therefore, the mass percentage of calcium (Ca) in CaO is approximately 71.43%, and the mass percentage of oxygen (O) is approximately 28.57%.