four gases were combined in a glass cylinder with these partial pressures:3.5 atm N2,2.8 atm, 0.25 atm At and 0.15 atm He. What is the mole fraction in the mixture? What is the mole fraction of Ar in the mixture?

Consider the laboratory on HPLC analysis of components in diet soft drinks. Your standard solutions for caffeine were prepared from a stock solution of 0.40 mg/mL caffeine, from which you drew, 1.0, 2.0, 3.0, 4.0 and 5.

What constitutes only 16% of earth's volume but 32% of earth's mass

Thermal energy can be transferred by conduction, convection, or radiation. You can see examples of these types of transfers all around you.

A substance that dissolves in water is said to be

A student calculated that the amount of NaCl that should form in the lab (theoretical yield) is 2.50 grams. The actual amount formed was only 2.30 grams. How would you calculate the student's percent yield? A) 92% B) 0.92% C) 108% D) 1.08 %

An ion of magnesium has 12 protons and a charge of + 2. how many electrons are in this ion? A. 2 B. 20 C. 12 D. 14

A mixture consists of sand and an aqueous salt solution. Which procedure can be used to separate the sand, salt, and water from each other? (1) Evaporate the water, then filter out the salt. (2) Evaporate the water, then filter out the sand.

Identify the components of a fuel cell. zinc-manganese hydrogen-oxygen nickel-metal hydride lithium ion nickel-cadmium

For the reaction hconh2 (g) ânh3 (g) + co (g), k = 4.84 at 400 k what can be said about this reaction at this temperature?

What would be the effect on the nucleus of an atom if it emitted one alpha particle and one gamma ray