What is the label reaction of

Na2O+H20->2NaOH ?

The chemical reaction you mentioned is the combination reaction of sodium oxide (Na2O) with water (H2O) to form sodium hydroxide (NaOH). This reaction is commonly known as the neutralization reaction.

To understand the label reaction, it is important to know what each component is:

- Na2O: Sodium oxide, which is a binary compound composed of two sodium (Na) atoms combined with one oxygen (O) atom.
- H2O: Water, which consists of two hydrogen (H) atoms combined with one oxygen (O) atom.
- NaOH: Sodium hydroxide, an ionic compound composed of one sodium (Na) ion and one hydroxide (OH) ion.

To determine the label reaction, you need to balance the chemical equation. Here's how you can do it:

1. Write down the given reactants and products: Na2O + H2O -> NaOH.
2. Count the number of each type of atom on both sides of the equation.
On the left side (reactants): 2 Na atoms, 1 O atom, 2 H atoms.
On the right side (product): 2 Na atoms, 1 O atom, 1 H atom.
3. Balance the equation by adjusting the coefficients in front of the reactants and products to make the number of atoms equal on both sides:
Na2O + 2 H2O -> 2 NaOH.

After balancing the equation, you can see that the label reaction is:
Sodium oxide (Na2O) reacts with water (H2O) to produce sodium hydroxide (NaOH).

This reaction is an example of a neutralization reaction, as it involves the combination of an acid (water acts as a weak acid here) and a base (sodium oxide) to produce a salt (sodium hydroxide) and water.