Question

5.Розставте коефіцієнти в хімічних рівняннях: Pb + O2 = PbO; К+ O2 = K20; NaNO3 = NaNO2 + O2;

Answer 1

2Pb+O2->2PbO
4K+O2->2K2O
2NaNO3-> 2NaNO2+O2

Answer 2

Coefficients in Chemical Equations:

When balancing chemical equations, coefficients are used to ensure that the number of atoms of each element is equal on both sides of the equation. Let's balance the given chemical equations:

1. Pb + O2 = PbO - The unbalanced equation is: Pb + O2 = PbO - To balance the equation, we need to ensure that the number of atoms of each element is the same on both sides. - Let's start by balancing the lead (Pb) atoms. There is one Pb atom on the left side, so we need one Pb atom on the right side as well. - Now, let's balance the oxygen (O) atoms. There are two O atoms on the right side, so we need to add a coefficient of 2 in front of the PbO on the left side. - The balanced equation is: Pb + O2 = 2PbO.

2. K + O2 = K2O - The unbalanced equation is: K + O2 = K2O - Let's balance the potassium (K) atoms first. There is one K atom on the left side, so we need two K atoms on the right side. - Now, let's balance the oxygen (O) atoms. There are two O atoms on the right side, so we need to add a coefficient of 1/2 in front of the O2 on the left side. - To avoid fractions, we can multiply the entire equation by 2 to get rid of the coefficient of 1/2. - The balanced equation is: 2K + O2 = 2K2O.

3. NaNO3 = NaNO2 + O2 - The unbalanced equation is: NaNO3 = NaNO2 + O2 - Let's balance the sodium (Na) atoms first. There is one Na atom on the left side, so we need one Na atom on the right side as well. - Now, let's balance the nitrogen (N) atoms. There is one N atom on the left side, so we need one N atom on the right side as well. - Finally, let's balance the oxygen (O) atoms. There are three O atoms on the right side, so we need to add a coefficient of 3/2 in front of the O2 on the left side. - To avoid fractions, we can multiply the entire equation by 2 to get rid of the coefficient of 3/2. - The balanced equation is: 2NaNO3 = 2NaNO2 + 3O2.

Please note that the coefficients in chemical equations represent the relative number of molecules or moles of each substance involved in the reaction.