At STP, 3.0 L of D2 reacts completely with 3.0 L of E, producing 1.5 L of a product. What is the formula of the product?
D2 + E = product
mols D2 = 3/22.4 = ?
mols E = 3/22.4 = ?
mols product = 1.5/22.4
However, when working with gases one can dispense with the 22.4 since that is a constant in all of the numbers; i.e., use L as if L = mols.
I would think the formula of the product is D4E2. Try this.
2D2 + 2E ==> D4E2
3......3......1.5