In any chemical compound the elements are always combined in the same proportion by__.

a) charge

b) mass

c) volume

d) density

Determine the molarity of 50 mL of HCl solution with unknown concentration, titrated with 75 mL of 4.0 M NaOH.

How many molecules of ethanol (c2h5oh) (the alcohol in alcoholic beverages) are present in 155 ml of ethanol? the density of ethanol is 0.789 g/cm3?

The reaction between hydrogen and oxygen to yield water vapor has ΔH∘=-484kJ: 2H2 (g) + O2 (g) →2H2O (g) ΔH∘=-484kJ How much PV work is done in kilojoules for the reaction of 3.20 mol of H2 with 1.

Predict how the gene pool will change over time Darwin's Natural selection sheet.

Cobalt 59 is a stable isotope and cobalt 60 is an unstable or radioactive isotope these two isotopes differ in the number of

Which of the following is a chemical property? A.) Ability to burn B.) Mass C.) Density D.) All of the above

What is the density of rock if it has a mass of 25 g?

In a popular classroom demonstration, solid sodium is added to liquid water and reacts to produce hydrogen gas and aqueous sodium hydroxide. part a write a balanced chemical equation for this reaction.

Calculate the vapor pressure lowering on an aqueous solution of glycerin that contains 180g of glycerin and 1000g of water at 25c. The vapor pressure of water at this temperature is 23.8torr.

Why does one Oxygen atom bond with two Hydrogen atoms to form water? Why don't they bond in a different ratio?