What's the difference?
The term populace refers to the people who live in a specific place, such as the inhabitants or community of a city or country. On the other hand, populous is an adjective that describes a place that has a large population or is densely inhabited.
Populace is a noun for the people living in a specific place, often used in socio-political contexts. Populous, by contrast, is an adjective describing a place with a high population density.
Source = grammarly
