automotive air bags inflate when sodium azide rapidly decomposes as shown in this equation: 2nan3(s) → 2na(s) + 3n2(g) what mass of nan3 is necessary to produce 70.0 l of n2 gas at 315 k and 1.20 atm? 141 g nan3 422 g nan3 723 g nan3 948 g nan3

141.0 g NaN₃.

Explanation:

It is a stichiometric problem.

Firstly, we should wright the reaction as a balanced equation:

2NaN₃ → 2Na + 3N₂

It is clear that 2.0 moles of NaN₃ decompose to 2.0 mole of Na and 3.0 moles of N₂.

Then we should convert the volume of N₂ (70.0 L) to moles via using the gas law of ideal gas: PV = nRT, n = PV / RT,

Where, P is the pressure of the gas in atm (P = 1.2 atm).

V is the volume of the gas in L(V = 70.0 L).

R is the general gas constant (R = 0.082 L.atm/mol.K).

T is the temperature in K(T = 315 K).

∴ n of N₂ = PV / RT = (1.2 atm) (70.0 L) / (0.082 L.atm/mol.K) (315 K) = 3.252 mole.

From the stichiometry:

2.0 moles of NaN₃ decomposes to → 3.0 moles of N₂

??? mole of NaN₃ decomposes to → 3.2520 moles of N₂

The number of moles of NaN₃ = (2.0 moles of NaN₃) (3.2520 moles of N₂) / (3.0 moles of N₂) = 2.168 mole.

Finally, we can convert the number of moles of NaN₃ to mass using the relation: m = n x molar mass.

Molar mass of NaN₃ = 65.0 g/mol.

the mass of NaN₃ = n x molar mass = (2.168 mole) (65.0 g/mol) = 140.92 g ≅ 141.0 g.

why do the isotopes of a particular element behave differently in nuclear reactions but the same in chemical reactions? chemical reactions involve changes to electrons in an atom; isotopes do not differ in electrons, and so they react the same way during chemical changes.

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.