Write balanced equation for:
1.$BF_{3}+LiH\rightarrow$
2.$B_{2}H_{6}+H_{2}O\rightarrow$
3.$NaH+B_{2}H_{6}\rightarrow$
4.$H_{3}BO_{3}\xrightarrow{\Delta }$
5.$Al+NaOH\rightarrow$
6.$B_{2}H_{6}+NH_{3}\rightarrow$

Hint: A chemical reaction is represented in the form of a chemical equation. The balanced term is used to specify the equality of the number of reactants and product in a reaction.

Complete answer:
- A balanced equation reaction is referred to an equation which contains equal numbers of each type of atom present on the reactants side as well as on the product side.
- The symbolic representation of a chemical reaction is called a chemical equation. The balanced equation is one in which the number of atoms or substances is equal on both sides of the equation.
- As we are already aware, mass can neither be created nor be destroyed, so the number of atoms which are present in the reactants must balance the number of atoms which are present in the products.
- Hence, if the law of conservation is not applicable for a reaction the chemical equation is not balanced.
- The balanced equation for the given reactions is shown below:
1.\begin{align*}2BF_{3}+6LiH\rightarrow B_{2}H_{6}+6LiF \end{align*}
In this reaction, boron trifluoride and lithium hydride react to produce diborane and lithium fluoride.
2.\begin{align*}B_{2}H_{6}+6H_{2}O\rightarrow 2H_{3}BO_{3}+6H_{2}\end{align*}
The diborane reacts with water to produce orthoboric acid and hydrogen gas.
3.\begin{align*}2NaH+B_{2}H_{6}\rightarrow 2NaBH_{4}\end{align*}
Sodium hydride reacts with diborane to produce sodium borohydride.
4.\begin{align*}H_{3}BO_{3}\xrightarrow{\Delta } HBO_{2}+ H_{2}O\end{align*}
\begin{align*}
4HBO_{2}\xrightarrow[-H_{2}O]{\Delta } H_{2}B_{4}O_{7}\xrightarrow[-H_{2}O]{\Delta } 2B_{2}O_{3}
\end{align*}
The thermal decomposition of boric acid leads to formation of meta-boric acid. The decomposition continues further to form boron trioxide.
5.\begin{align*}Al+3NaOH\rightarrow Al(OH)_{3}+3Na\end{align*}
The activated aluminium metal undergoes reaction with sodium hydroxide to produce aluminium hydroxide and metallic sodium.
6.\begin{align*}3B_{2}H_{6}+6NH_{3}\rightarrow 3B_{3}N_{3}H_{6}+12H_{2}\end{align*}
The diborane reacts with ammonia to generate borazine and hydrogen gas.

Note:
The number written before the reactants are called reactant coefficients and that of product are called product coefficients. A balance chemical equation gives information about the relative formation of the products.