Answer:
0.196 grams of K2S reacted
Step-by-step explanation:
When hydrochloric acid is poured over potassium sulfide, 43.7 mLmL of hydrogen sulfide gas is produced at a pressure of 758 torrtorr and 26.0 ∘C
How much potassium sulfide has reacted in grams?
Step 1: Data given
Volume of hydrogen sulfide (H2S) produced = 43.7 mL
Pressure = 758 torr = 758/760 = 0.9973684 atm
Temperature = 26.0 °C = 273 + 26 = 299 K
Step 2: The balanced equation
2 HCl + K2S → H2S + 2 KCl
Step 3: Calculate moles H2S
p*V = nRT
n = (pV)/(RT)
⇒ with n= the number of moles of H2S
⇒ with p = the pressure = 0.9973684 atm
⇒ with V = the volume of the gas = 43.7 mL = 0.0437 L
⇒ with R = the gas constant = 0.08206 L*atm/K*mol
⇒ with T = The temperature = 26°C = 299 Kelvin
n = (0.9973684 * 0.0437)/ (0.08206*299)
n = 0.001776 moles H2S
Step 4: calculate moles of K2S
For 2 moles HCl we need 1 mol K2S to produce 1 mol H2S and 2 moles KCl
For 0.001776 moles H2S produced, we need 0.001776 moles K2S
Step 5: Calculate mass of K2S
Mass K2S = moles K2S * molar mass K2S
Mass K2S = 0.001776 moles * 110.26 g/mol
Mass K2S = 0.196 grams K2S
0.196 grams of K2S reacted