How many ml of 0.10M NaOH solution are needed to neutralize 15 ml of a 0.20M H3PO4 solution?? :confused:

1. Determine the reactants and products.
2. Write and balance the reaction using the reactants and products.
3. Determine the number of moles in 15 mL of 0.20 M H3PO4
4. From the balanced equation, determine the ratio of Moles of NaOH/H3PO4 that will react. Multiply the number of moles of H3PO4 that you determined in #3 by this ratio.
5. Determine the number of mL of 0.10M NaOH that are required to supply the number of moles determined in #4.

Remember that 0.10M = 0.10 moles/Liter

Why does oil and vinegar salad dressing have two separate layers

Oil and vinegar are two immiscible liquids, that's because of the structure of the oil which is big and contains a long hydrophobic part. Hence, it will not mix with water or alcohol and form separate layers. In fact, oil is less dense, and therefore will float.

You should have started another thread though.