How many molecules are in 0.25 moles of CH4

How many significant figures are in 0.00044

John walks at a steady speed of 3 mph. How long will it take him to travel 24 miles?

How many moles of nitrogen are in 66.0 g of nitrous oxide?

How does your body respond differently the second time it is exposed to a pathogen than the first time it was exposed to the same pathogen?

A chemist prepares a solution of copper (II) sulfate CuSO4 by measuring out 79. g of copper (II) sulfate into a 500. mL volumetric flask and filling the flask to the mark with water.

How many milliliters of a 0.7% stock solution are required to make 2 l of 0.2% solution? how many ml of solvent will be required to carry out the dilution?

What percentage of the naphthalene molecules emitted a photon?

In an endothermic reaction, heat is absorbed from the surroundings. How does this affect entropy? A. The particles in the surroundings move slower and have decreased entropy. B.

The temperature of a sample of liquid water changes from 50°C to 30°C. Which statement best explains the change that must happen at the molecular level? A. The molecules move more quickly and their average kinetic energy increases. B.

The most important reason why solid sodium hydroxide is not used as a primary standard is