Question

Определите массу оксида Ca образовавшегося в результате горения 20г Ca

Answer 1

  20 г                                 Х г

  2Са      +      О2     =      2СаО

n = 2 моль                       n = 2 моль

М= 40 г/моль                  М= 56 г/моль

m = 80 г                          m = 112 г

20 г Са     -   Х г СаО

80 г Са    -    112 г СаО

m(CaO) = 20 * 112 / 80 = 28 г

Answer 2

I can help you with your question. To find the mass of calcium oxide formed as a result of burning 20 grams of calcium, you need to use the following equation:

$$Ca + O_2 \rightarrow CaO$$

According to the law of conservation of mass, the mass of the reactants is equal to the mass of the products. Therefore, you can write a proportion:

$$\frac{m(Ca)}{M(Ca)} = \frac{m(CaO)}{M(CaO)}$$

where $m$ is the mass and $M$ is the molar mass. You can find the molar masses of calcium and calcium oxide from the periodic table:

$$M(Ca) = 40 \text{ g/mol}$$ $$M(CaO) = 40 + 16 = 56 \text{ g/mol}$$

Substituting the values and solving for $m(CaO)$, you get:

$$m(CaO) = \frac{m(Ca) \times M(CaO)}{M(Ca)}$$ $$m(CaO) = \frac{20 \text{ g} \times 56 \text{ g/mol}}{40 \text{ g/mol}}$$ $$m(CaO) = 28 \text{ g}$$

Therefore, the mass of calcium oxide formed is 28 grams. This answer is consistent with the web search results. I hope this helps.