3Fe+4H2O (yields) Fe3O4+4H2. What is the mole ratio of Fe3O4 to Fe?

A - 1:3

B - 1:4

C - 3:1

D - 4:3

1. 1.204 x 1024 atoms He = ? moles He

How many moles of MgSiO3 are in 233 g of the compound?

Which of the following solutions has a 1.0 M? A. 0.050 mol of solute in 25.0 ml solution B. 2.0 mol of solute in 500.0 ml of solution C. both answers are correct D. there is not correct answer

Which compound forms a network solid? a: calcium bromide b: hydrogen bromide c: silicon dioxide d: Carbon dioxide

A 12.34 ml solution with an unknown salt concentration had a mass of 10.25g. when the water was evaporated from the solution 4.78 g of NaCl remained. Calculate the mass-mass percent NaCl concentration in the solution.

Substance a has a density of 3.0 g/cm3 and substance b has a density of 4.0 g/cm3. in order to obtain equal masses of these two substances, the ratio of the volume of a to the volume of b will be equal to

Calculate the mass (in grams) of cobalt that has the same number of atoms as 521 mg of silicon.

You spill a little bit of olive oil on your hands. You wash off the oil with soap and water. How does the soap get the oil off your hands?

Which statement best describes position of the Earth in the Solar System?

Which best describes a swimming pool? 1.) it is a solute 2.) it is a solvent 3.) it is a solution 4.) it is a reactant 5.) it is a product