If your trike only goes about 5 to 8 MPH with the belt drive then it might work but the ratio with the chain will give you almost double the speed and cut your range drastically. If your trike already goes 15 to 20 MPH the motor may not have enough power to move the trike on a small hill with the new ratio.
If you could give us more information, motor, battery pack size, current speed, and weight I might be able to give you a better answer.
Short answer: NO
If your trike only goes about 5 to 8 MPH with the belt drive then it might work but the ratio with the chain will give you almost double the speed and cut your range drastically. If your trike already goes 15 to 20 MPH the motor may not have enough power to move the trike on a small hill with the new ratio.
If you could give us more information, motor, battery pack size, current speed, and weight I might be able to give you a better answer.