Question

Are combustion reactions always accompanied by flame? Give example.

Answer 1

Solution:

No, combustion reactions are not always accompanied by flames. For example - The burning of coal.

Combustion

Burning, or combustion, is a high-temperature exothermic redox chemical process between a reductant (fuel) and an oxidant (typically atmospheric oxygen).

Combustion without flames

When most substances undergo combustion some part of them keeps turning into gas which then combines with oxygen to produce flames. But some substances like coal for example don't produce any flames during combustion.

Conclusion

Therefore, it is not necessary that combustion is always accompanied by flame. Example - The burning of coal.