How would I solve this problem?

15 = 10z/[2 - (5x4) ]

In the reaction between phosphoric acid and ammonia, a compound forms containing 28.2 grams nitrogen, 8.1 grams hydrogen, 20.8 grams phosphorus, and 42.9 grams oxygen by mass. a. what is the empirical formula for this compound

For a given substance, what links moles to moles?

The volume of a 12.4 g metal pellet is measured by water displacement. It is added to a graduated cylinder filled with water, and the level rises from 10.00 mL to 13.65 mL. What is the density of the metal?

Surface currents are mainly caused by prevailing winds. What is the best synonym for "prevailing?"

A compound held together by ionic bonds is called a salt covalent molecule diatomic molecule polar compound

What is a large oval structure that directs all of the cells activities?

HBr + H₂SO₄ SO₂ + Br₂ + H₂O What is the oxidation number of the oxidizing agent? What is the oxidation number of the reducing agent?

How do find the volume of 60.0g of ether if the density is. 70g/mL?

A population of crabs live on a light-colored sandy beach. In this environment there is a population of birds that eat the crabs. One year, there is a volcanic eruption near the beach and dark volcanic ash covers the beach.

It would take one light year to travel to the sun? True or false?