Are these right?

which of the following factors does not affect the behavior of a gas in a closed container?

the number of particles
the average kinetic energy*
the cohesive forces within the gas
the size of the container

which is not a possible sign of a physical change?

change in appearance
change in volume
the release of energy*
change in color

which of the following types of substances would be least likely to dissolve in water?

nonpolar molecule like cholesterol*
polar molecule like ethyl alcohol
ionic compound, such as magnesium chloride
polar mole like the

Apure solvent has a vapor pressure the vapor pressure of a solution. a. equal to b. lower than c. higher than

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)

If 15 drops of ethanol from a medical dropper weight 0.60g, how many drops does it takes from a dropper to dispense 1.0ml of ethanol? the density of ethanol is 0.80g/ml