Question

KNO3 + C12H22O11 = ?
When Heated​

Answer 1

when potassium nitrate and sugar are heated, potassium nitrate converts into potassium carbonate and sugar oxidises into carbon dioxide.

a skeleton chemical reaction is ....

$C_{12}H_{22}O_{11} + KNO_3\rightarrow K_2CO_3 + CO_2 + N_2 + H_2O$

for balancing this equation, seperate chemical reaction into half redox reaction.

step 1: $NO_3^-\rightarrow N_2$

or, $2NO_3^-+12H^+\rightarrow N_2+6H_2O-10e^-$......(1)

step 2 : $C_{12}H_{22}O_{11}+14H_2O\rightarrow 11CO_2+CO_3^{2-}+50H^++48e^-$.....(2)

from equations (1) and (2),

24 × eq(1) + 5 × eq (2)

or, $48NO_3^-+288H^++5C_{12}H_{22}O_{11}+70H_2O\rightarrow24N_2+144H_2O+55CO_2+5CO_3^{2-}+250H^+$

or, $48NO_3^-+5C_{12}H_{22}O_{11}+38H^+\rightarrow 24N_2+74H_2O+55CO_2+5CO_3^{2-}$

or, $48KNO_3+5C_{12}H_{22}O_{11}+38H^+\rightarrow 24N_2+48K^++74H_2O+(19CO_3^{2-}+36CO_2)+5CO_3^{2-}$

or, $48KNO_3+5C_{12}H_{22}O_{11}+38H^+\rightarrow 74H_2O+24K_2CO_3+36CO_2+24N_2$ This is balanced chemical equation

Answer 2

Potassium nitrate + sugar ----- heated---- potassium carbonate + carbon dioxide.  

Here, potassium nitrate (crystalline salt)  converts into potassium carbonate and sugar oxidise into carbon dioxide.  

This reaction generates heat and emit light .

This act as a good rocket fuel as the solids are converting directly into gases.

Nitrate is the source of oxygen and hence it is good oxidising agent.

Potassium nitrate reacts with many compounds, acids, sugar and sulfur.

On  ignition of  the nitrate, the sugar burns quickly and heat is produce.