Yes, it is a Sansevieria.
The problem with the leaf could be a few things. The best you can hope for is its shedding an older leaf. Plants will discard old leaves, once the reach a certain point in maturity. If the plant is health and getting all of its needs met it should replace it with more than one leaf.
The worst is its rotting. You should remove that topdressing so you can have a better look at the soil. Is the soil wet. If it is wet the chances are you are over-watering. It is easy to over water when you can not see the soil. It is best to be able to see and feel the soil before you water. Some people are able to do it by weight. Lifting it when it is dry and when it is wet so they know the difference. Then you don't have to see the soil. The other technique is just to stick you finger in the soil the depth of 2". If the soil is moist or wet you do not water. It is only when you can not feel any moisture do you water. The last technique is a bamboo stick (barbeque skewer). Insert in soil. Leave for 30 min. Pull out soil. Look at it and feel it. If it is wet don't water. If it is dry water.
If you have over-watered, let it dry completely out for a few days before you water again. Give those roots some time to die off and seal off the danger of spreading the rot.
If you start to get a problem on many leaves, I would take it out of the soil. Wash all the soil off the roots and repot it in better draining soil. Buy a bag of cactus & succulent potting mix and mix with same amount of perlite. Use this as your soil.
There are a couple other things it could be, over-fertilising, or some kind of other chemical/salt build up in the soil. Some people are unable to use the tap water becuase it has been overly treated with chemical. Or they have a water softener. Both of there will show up are brown tips on leaves. But, I would expect to see it on more leaves.