Convert mass and radius to Torque. The force would be distributed between fastener wall contact areas unevenly with very high pressure on the bottom edge puncturing the wall with the same torque but increased force due to the reduction in radius ratio.
This needs a large brace to work., as well as a rigid area for the fastener to withstand the pressure on the wall.
Say the arm is 2 inches vertically at the base where it is hung by the fastener and the distance between the fastener and the point of pressure is 1.5 inches.
This means your fastener is being pulled out by a nominal force of 144# and the wall on the 1.5 in below must resist a nominal compression force of 144#.
Both the tension and compression should be multiplied by a safety factor of say 1.8.