Is it permissible to contribute to building a mosque with money that is a grant from the state to the unemployed?

There is no harm for the unemployed in spending the state grant as they wish, if the state has not specified a particular use for it. Building mosques is among the best ways to spend the grant, due to the great good and reward it entails. The Messenger of Allah, peace and blessings be upon him, said: "Whoever builds a mosque seeking thereby the Face of Allah, Allah will build for him a similar house in Paradise."