I would recommend installing chains on all four wheels if you have two sets.
If only 1 set, this guy explained it well.
• Snow chains mounted on all 4 with 4WD/AWD - ideal lateral stability, perfect acceleration, crisp steering, super braking. However, part time systems will show some understeer (turns are wider than intended). Full time 4WD systems are best. This is what everyone should have for snow and ice. Be careful anyway.
• Snow chains mounted on front axle with 4WD/AWD - good acceleration, good steering, good braking. However, since the rear wheels have no lateral guidance, the rear end might come around - fast. Not good. Feather your brakes. Go slow.
• Snow chains mounted on rear axle with 4WD/AWD - good acceleration, lousy steering (no lateral guidance), marginal braking (remember, 80% of brake force is created at front wheels and without chains that ain't happening). No fishtailing. Best compromise for 4WD with only one pair of chains. Go slow.
With only one pair, put them in the back, that's what is recommended in the owners guide