Question

8 класс. Расстановка коэффициентов Вариант I 1. Na + Cl2 -> NaCl 2. Al + Cl -> A1C13 3. FeCl2 + Cl2-> FeCl3 4. C3H, + 02 -> C02 + H20 5. Cu + 02 - CuO 6. Fe(OH)3 -> Fe203 + H2O 7. Al + CuBr2-> AlBr3 + Cu 8. Ca(OH)2 + Na3P04-> Caз(P04)2 + NaOH 9. К20 + н20-> кон 10. NO2 -> NO + 02 11. B2H6 + 02 -> B2O3 + H20 12. C5H10 + 02-> C02 + H20

Answer 1

Ответ:

1. 2Na + Cl2 -> 2NaCl

2. 2Al + 3Cl2 -> 2A1C13

3. 2FeCl2 + Cl2-> 2FeCl3

4. C3H, + 02 -> C02 + H20 нет индекса у первого вещества

5. 2Cu + 02 -> 2CuO

6. 2Fe(OH)3 -> Fe2O3 + 3H2O

7. 2Al + 3CuBr2-> 2AlBr3 + 3Cu

8. 3Ca(OH)2 + 2Na3P04-> Caз(P04)2 + 6NaOH

9. К20 + H2O -> 2KOH

10. 2NO2 -> 2NO + O2

11. B2H6 + 302 -> B2O3 + 3H20

12. 2C5H10 + 1502-> 10C02 + 10H20

Answer 2

8 класс. Расстановка коэффициентов. Вариант I

1. Na + Cl2 -> NaCl 2. Al + Cl2 -> AlCl3 3. FeCl2 + Cl2 -> FeCl3 4. C3H8 + O2 -> CO2 + H2O 5. Cu + O2 -> CuO 6. Fe(OH)3 -> Fe2O3 + H2O 7. Al + CuBr2 -> AlBr3 + Cu 8. Ca(OH)2 + Na3PO4 -> Ca3(PO4)2 + NaOH 9. K2O + H2O -> KOH 10. NO2 -> NO + O2 11. B2H6 + O2 -> B2O3 + H2O 12. C5H10 + O2 -> CO2 + H2O

Note: The given chemical equations represent reactions between different substances. The goal is to balance the equations by adjusting the coefficients in front of each compound or element to ensure that the number of atoms on both sides of the equation is equal.

Let's go through each equation and balance them:

1. Na + Cl2 -> NaCl - The equation is already balanced. There is one sodium (Na) atom on both sides and two chlorine (Cl) atoms on both sides.

2. Al + Cl2 -> AlCl3 - The equation is not balanced. There is one aluminum (Al) atom on the left side and three chlorine (Cl) atoms on the right side. - To balance the equation, we need to put a coefficient of 2 in front of Al on the left side: 2Al + 3Cl2 -> 2AlCl3.

3. FeCl2 + Cl2 -> FeCl3 - The equation is not balanced. There is one iron (Fe) atom on the left side and three chlorine (Cl) atoms on the right side. - To balance the equation, we need to put a coefficient of 2 in front of FeCl2 on the left side: 2FeCl2 + 3Cl2 -> 2FeCl3.

4. C3H8 + O2 -> CO2 + H2O - The equation is not balanced. There are three carbon (C) atoms on the left side and only one carbon atom on the right side. - To balance the equation, we need to put a coefficient of 3 in front of CO2 on the right side and a coefficient of 4 in front of H2O on the right side: C3H8 + 5O2 -> 3CO2 + 4H2O.

5. Cu + O2 -> CuO - The equation is already balanced. There is one copper (Cu) atom on both sides and one oxygen (O) atom on both sides.

6. Fe(OH)3 -> Fe2O3 + H2O - The equation is not balanced. There is one iron (Fe) atom on the left side and two iron (Fe) atoms on the right side. - To balance the equation, we need to put a coefficient of 2 in front of Fe(OH)3 on the left side: 2Fe(OH)3 -> Fe2O3 + 3H2O.

7. Al + CuBr2 -> AlBr3 + Cu - The equation is already balanced. There is one aluminum (Al) atom on both sides and three bromine (Br) atoms on both sides.

8. Ca(OH)2 + Na3PO4 -> Ca3(PO4)2 + NaOH - The equation is already balanced. There is one calcium (Ca) atom on both sides, three phosphorus (P) atoms on both sides, eight hydrogen (H) atoms on both sides, and six oxygen (O) atoms on both sides.

9. K2O + H2O -> KOH - The equation is already balanced. There are two potassium (K) atoms on both sides and two oxygen (O) atoms on both sides.

10. NO2 -> NO + O2 - The equation is already balanced. There are two nitrogen (N) atoms on both sides and four oxygen (O) atoms on both sides.

11. B2H6 + O2 -> B2O3 + H2O - The equation is not balanced. There are six hydrogen (H) atoms on the left side and only two hydrogen atoms on the right side. - To balance the equation, we need to put a coefficient of 3 in front of H2O on the right side: B2H6 + 3O2 -> B2O3 + 3H2O.

12. C5H10 + O2 -> CO2 + H2O - The equation is not balanced. There are 10 hydrogen (H) atoms on the left side and only two hydrogen atoms on the right side. - To balance the equation, we need to put a coefficient of 5 in front of H2O on the right side: C5H10 + 8O2 -> 5CO2 + 5H2O.

These are the balanced chemical equations for the given reactions.