Question

write 5 endothermic reaction

Answer 1

For example
When a small quantity of ammonium chloride (NH4Cl) is dissolved in water in a test tube, the tube becomes colder than before. During this chemical reaction heat is absorbed from the surroundings (test tube).
NH4Cl(s) + H2O(l) →→ NH4Cl(aq) - heat
When crystals of sodium thiosulphate (Na2S2O3.5H2O), commonly called hypo, are dissolved in water, a cooling effect takes place.
Na2S2O3.5H2O + H2O →→ Ns2SO3(aq) - heat
One mole of nitrogen reacts with one mole of oxygen to form two moles of nitric oxide. 180.5kJ of heat is absorbed at constant temperature and the reaction may be expressed as:
N2(g) + O2(g) + 180.5 KJ →→ 2NO(g)
or
N2(g) + O2(g) →→ 2NO(g) ΔΔ H = + 180.5 KJ
Similarly,
C(s) + 2S(s) →→ CS2(g) ΔΔ H = + 92.0 KJ

SnO2(g) + 2C(s) →→ Sn(s) + 2CO2(g) ΔΔ H = + 360.0 KJ

Answer 2

1. H2O → H2 + O
2.Fe2O3 + 2Al → 2 Fe + Al2O3
3.N2 + O2 → 2NO


I only know these three.
Hope it helps you