156 grams of sodium sulfide, na₂s, is dissolved in 1000 ml of solution. determine the molarity (m).

Explanation:

Step1: Calculate molar mass of Na₂S

The molar mass of Na is 22.99 g/mol and S is 32.07 g/mol. For Na₂S, molar mass $M_{Na_2S}=2\times22.99 + 32.07=78.05$ g/mol.

Step2: Calculate moles of Na₂S

Use the formula $n=\frac{m}{M}$, where $m = 156$ g and $M = 78.05$ g/mol. So $n=\frac{156}{78.05}\approx2$ mol.

Step3: Calculate molarity

The volume $V = 1000$ mL = 1 L. Molarity $M=\frac{n}{V}$, substituting $n = 2$ mol and $V = 1$ L, we get $M = 2$ mol/L.

Answer:

2