For chemistry students · 4 minute read
What happens when hydrogen sulfide and sodium hydroxide react?
With two equivalents of sodium hydroxide, hydrogen sulfide forms sodium sulfide and water in the supported equation.
- Balanced equation
- H2S(g) + 2NaOH(aq) -> Na2S(aq) + 2H2O(l)
- Model and safety boundary
- The fixed result assumes excess base and contained gas handling. It cannot predict gas escape or exposure.
Your study goal: Explain the two-to-one base ratio and distinguish sulfide from hydrosulfide.
Open the prepared exampleThe exact supported pair opens in a beaker. Nothing runs until you select Analyze.
Supported prediction
H2S(g) + 2NaOH(aq) -> Na2S(aq) + 2H2O(l)
What the equation means
Hydrogen sulfide transfers both acidic protons to excess sodium hydroxide to form sodium sulfide and water. This equation assumes two equivalents of base and a contained gas-handling system. With one equivalent, sodium hydrosulfide would form instead.
Expected observation
No gas-production cue belongs to this equation: hydrogen sulfide starts as a reactant
No gas-production cue belongs to this equation: hydrogen sulfide starts as a reactant. OmniLab does not display gas capture or pH.
Read the equation
Three details that explain the result
Connect the coefficients and formulas to the gas, solution, and visible cue.
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Count two acidic protons
H2S can transfer two protons. Complete neutralization needs two OH- ions from two NaOH units.
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Name the salt
Two sodium ions balance one sulfide ion in Na2S. Two water molecules account for the transferred protons.
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Keep the alternate outcome separate
With one base equivalent, sodium hydrosulfide can form instead. OmniLab returns only the excess-base equation.
Three safety notes
Read these before any physical experiment
- 01
Run this only in a specialist gas laboratory.
- 02
Use gas detection and ventilation, and never rely on odor.
- 03
Control ignition sources and collect sulfide-containing hazardous waste without adding acid.
Common questions
What students usually ask next
Use these distinctions to move from the visible reaction to the particle-level explanation.
Why is there a 2 before NaOH?
Two hydroxide ions are needed to remove both acidic protons in the stated complete-neutralization equation.
Is smell a safe test for hydrogen sulfide?
No. Odor cannot establish safety. This virtual guide is no substitute for specialist gas controls.
Keep exploring
Connect this observation to another reaction
These guides use the same pattern: predict the equation, identify the visible cue, then check what the virtual model leaves out.
See how the full virtual lab works