Would the grease spell with a flask of acid used as a power component work with burning spell?

Question

This question made me wonder whether this works.

A flask of acid can be used as a power component to add 1 point/ of acid damage per round to the effect of grease.

Grease (M): The grease is acidic and deals 1 point of acid damage per round to any creature in the area or holding the greased object.

Could I cast a burning grease with a flask of acid as a power component on an opponent's armor so that s/he is dealt 1 point of acid damage on round 1, 3 points of acid damage for the rest of the duration and 2 points on the round after the spell ends to the opponent?

When cast on CL 5 (when you get level 3 slots) that would be 5 minutes duration, which is 50 rounds.

Most armors should survive that because of hardness but unless it is removed that would mean 150 points of damage.

Edit: I missed that the feat mentions needing the acid or fire descriptor when I checked it. Sorry That should not have happened.

Answer 1

No, unless you can add a fire/acid descriptor to the spell

Burning Spell clearly says that the spell must have the acid or fire descriptor, however, there are ways to change a spell descriptor to include acid/fire.

Such as the Admixture Wizard's Arcane School:

Versatile Evocation (Su): When you cast an evocation spell that does acid, cold, electricity, or fire damage, you may change the damage dealt to one of the other four energy types. This changes the descriptor of the spell to match the new energy type. Any non-damaging effects remain unchanged unless the new energy type invalidates them (an ice storm that deals fire damage might still provide a penalty on Perception checks due to smoke, but it would not create difficult terrain). Such effects are subject to GM discretion. You can use this ability a number of times per day equal to 3 + your Intelligence modifier.

The Sorcerer Bloodlines that deal with elemental damage, such as Elemental, Efreeti and Shaitan bloodlines, all got an ability that adds fire or acid damage to the spell descriptor, such as:

Bloodline Arcana: Whenever you cast a spell that deals energy damage, you can change the type of damage to fire. This also changes the spell’s descriptors to match this energy type.

The Elemental Matamagic Rod however does not change the spell's type, as it works like Elemental Spell feat, which doesn't include that specific ruling.

The Bloatmage can also have the same powers as those sorcerer bloodlines mentioned before, using their 10th level ability Absorb Bloodline.

And finally, this is really stretching it, but seems to be legal from a rules a written standpoint:

All Summon Monster spells seems to be valid targets for Burning Spell.

When you use a summoning spell to summon a creature with an alignment or elemental subtype, it is a spell of that type.

Answer 2

Burning Spell says:

You cause creatures to take extra damage when you affect them with a spell that has the acid or fire descriptor.

Benefit: The acid or fire effects of the affected spell adhere to the creature, causing more damage the next round. When a creature takes acid or fire damage from the affected spell, that creature takes damage equal to 2x the spell’s actual level at the start of its next turn. The damage is acid or fire, as determined by the spell’s descriptor. If a burning spell has both the fire and acid descriptor, the caster chooses what kind of damage is dealt by the burning spell effect.

By the letter of the rules, since Grease doesn't have the acid descriptor, and since it doesn't say that using Acid as a Power Component adds the descriptor, then the spell doesn't qualify for the effects of Burning Spell.

Your GM may rule that, because it adds an acid effect it should act as if it has the acid descriptor, but that would be a houserule.