49 in. W x 22 in. D Cultured Marble Vanity Top in Solid White with Solid White Basin

Yes! And that also helps drain the sink.

19 inches

Yes it can if you buy a single hole faucet that comes with a plate that will cover the two extra holes. Most of them are going to come that way if you buy a good faucet like Moen. Just make sure it shows that extra plate on the box.

The backsplash is four (4) inches high.

Yes, it is pure white. See my review post for a photo.

I would think so. Just measure the vanity you want to put it on and compare those measurements with those Home Depot lists for the vanity top,

Yes, it is a separate purchase

The key measurement is from the center drain. This one is 24 1/2" to each side. The vanity top I replaced was 48 1/2" BUT it was exactly 24 1/2" to the right (wall) side. This meant its replacement would center up over the drain and give us 1/2" more on the open (left) side. So it fit. So: 1. Measure from the drain to the wall side edge of your current vanity. If it is 24 1/2", it should work as long as you can fit the extra 1 1/2" on the non wall side. That is it doesn't end up impinging on the toilet space.

The measure you must be concerned with is the distance from the drain to the side. This is 24 1/2". The vanity I replaced was 48 1/2", but the drain was 24 1/2" from the right (wall) side. This meant that this 49" vanity had a drain centered perfectly at 24 1/2". The extra 1/2", in my case, was on the open side next to the toilet. No problem. So measure the distance from your current drain to both edges. I would bet, one side is 24 1/2". As long as you don't have walls on both ends, this should be fine. The side splash that matches this is sold separately, and fits on top of the counter so as not to need any adjustment.

Design House also supplies the model #553396 61 in. W Cultured Marble Vanity Top in White with Solid White Bowl under HD internet #204189935, that item is currently out of stock at the moment, but expected to be back in stock and available for purchase within the next week. They also supply the model #553313 61 in. W Cultured Marble Vanity Top with Solid White Double Bowl under HD internet #204189868 that is currently in stock and available for purchase.