Numford
Potassium and water

Balance K + H₂O → KOH + H₂

2 K(s) + 2 H₂O(l) → 2 KOH(aq) + H₂(g)

  • Displacement reaction
  • 2 : 2 : 2 : 1 coefficients

Balance an equation

Arrow. Type -> or =. Subscripts. Plain digits: H2SO4, Ca(OH)2, CuSO4.5H2O. Charges. Fe3+, OH-, SO4 2-, and e- for an electron. States. (s), (l), (g) and (aq) are kept. Coefficients you type are checked.

2K(s)+2H₂O(l)→2KOH(aq)+H₂(g)

Balanced

Atoms on each side

AtomAs writtenleft : rightBalancedleft : right
K1:12:2
H2:34:4
O1:12:2

Check atoms

How to balance it
Working

How to balance it, step by step

  1. Count the atoms of each element on both sides, as written.
  2. Start with the biggest formula, H₂O: put 1 in front of it.
  3. O: 1 on the left. Put 1 in front of KOH.
  4. K: 1 on the right. Put 1 in front of K.
  5. H: 2 on the left, 1 already on the right. Put 1/2 in front of H₂ (1/2 × 2 = 1).
  6. Clear the fraction: multiply every coefficient by 2.
  7. Check: K 2 = 2, H 4 = 4, O 2 = 2. Balanced.
The reaction

What happens

It is a displacement reaction: a more reactive element pushes a less reactive one out of its compound. Potassium reacts even more violently than sodium with cold water, giving potassium hydroxide and hydrogen, which catches fire at once.

Questions

Potassium and water: quick answers

What is the balanced equation for potassium and water?

2 K(s) + 2 H₂O(l) → 2 KOH(aq) + H₂(g). The coefficients are 2, 2, 2 and 1. Each side then has 2 K, 4 H and 2 O.

What type of reaction is potassium and water?

It is a displacement reaction: a more reactive element pushes a less reactive one out of its compound. Potassium reacts even more violently than sodium with cold water, giving potassium hydroxide and hydrogen, which catches fire at once.

How do you balance K + H₂O → KOH + H₂?

Start with the biggest formula, H₂O: put 1 in front of it. O: 1 on the left. Put 1 in front of KOH. K: 1 on the right. Put 1 in front of K. H: 2 on the left, 1 already on the right. Put 1/2 in front of H₂ (1/2 × 2 = 1). Clear the fraction: multiply every coefficient by 2. Never change a subscript, because that would change the substance.

Balance your own equation