Nitrogen has an atomic number of 7, with the electron configuration of 1s² 2s² 2p³, resulting in 3 unpaired electrons in the 2p subshell.

According to the law of conservation of mass, the total mass of the products is equal to the total mass of the reactants, which is 10 g + 20 g = 30 g.

Concentration = mass/volume = 10 g / 0.5 L = 20 g/L.

pOH = 14 - pH = 3, [OH-] = 10^-3 M.

All the given pairs can undergo double displacement reactions.

2H2 + O2 → 2H2O. 1 mole of water weighs 18 g, so 2 moles produce 36 g. Thus, 18 g of water is produced from 1 mole of O2.

2 moles of H2 and 1 mole of O2 produce 2 moles of H2O. The molar mass of water is 18 g/mol, so 2 moles produce 36 g.

From 2 moles of Fe, 2 moles of FeCl3 are produced. Therefore, from 4 moles of Fe, 4 moles of FeCl3 are produced.

2 moles of Na produce 2 moles of NaCl. Molar mass of NaCl = 58.5 g/mol. Therefore, 2 moles of NaCl = 2 × 58.5 g = 117 g.

4 moles of Na produce 4 moles of NaCl. Molar mass of NaCl = 58.5 g/mol. Therefore, 4 × 58.5 = 236 g.

From 2 moles of Na, 2 moles of NaCl are produced. Therefore, from 4 moles of Na, 4 moles of NaCl are produced.

When a gas is compressed, the volume decreases because the particles are forced closer together.

The balanced equation for the combustion of propane is C3H8 + 5O2 → 3CO2 + 4H2O.

The chemical formula for sulfuric acid is H2SO4, which consists of two hydrogen atoms, one sulfur atom, and four oxygen atoms.

The balanced equation is C4H10 + 6O2 → 4CO2 + 5H2O, so the coefficient of O2 is 6.

The conjugate base of sulfuric acid (H2SO4) is HSO4-.

Adding a base to a weak acid will neutralize some of the acid, increasing the pH.

Adding a base to hydrochloric acid will neutralize it, resulting in an increase in pH.

Adding a base to an acidic solution increases the pH, making it less acidic.

Adding a strong acid to a weak base will decrease the pH of the solution.

The electron configuration of chlorine is 1s² 2s² 2p⁶ 3s² 3p⁵, filling up to the 3p subshell.

Carbon has an atomic number of 6, and its electron configuration is 1s² 2s² 2p².

Oxygen has 8 electrons, and its electron configuration is 1s² 2s² 2p⁴.

The empirical formula is obtained by dividing the subscripts by the greatest common divisor, which is 2. Thus, C6H12 becomes C3H6.

The empirical formula is obtained by dividing the subscripts by the greatest common divisor, which is 2. Thus, C6H12 becomes C3H6.

The concentration of hydrogen ions is calculated as [H+] = 10^-pH = 10^-5 M.

The concentration of hydrogen ions is calculated using [H+] = 10^-pH.

Normality (N) is calculated as the molarity (M) multiplied by the number of equivalents (n).

The formula for calculating pH is pH = -log[H+].

The IUPAC name for CH3-CH2-COOH is propanoic acid, as it has three carbon atoms in the longest chain.