How much gr should a 1.6 quart gas tank Lawnmower be able to cut before having to be refilled?

I just bought a self-propelled, walk behind lawn mower and as I was almost done cutting my half acre lawn, it started sputtering and stopped. I look in the gas tank and it looked like there was some gas in there but I added more. Should a gas tank that size be able to cut a full half acre?