**4. Conclusions**

Darcy–Forchheimer flow of viscous nanofluid due to a rotating disk with binary chemical reaction and Arrhenius activation energy was studied. The shooting algorithm leads to the solutions of dimensionless quantities. We noticed that temperature rises for larger thermal Biot number. Temperature is less in the absence of thermal Biot number. Enhancing concentration Biot number leads to higher concentration and thickness of concentration boundary layer. An increase in activation energy leads to higher temperature. We further demonstrated that enhancement in chemical reaction parameter gives a reduction in the curves of concentration.

**Author Contributions:** All the authors have contributed equally in all parts.

**Funding:** This research was funded by University of Malaya gran<sup>t</sup> number IIRG 001C-2019.

**Acknowledgments:** The project is partially sponsored by University of Malaya gran<sup>t</sup> No: IIRG 001C-2019.

**Conflicts of Interest:** The authors declare no conflict of interest.
