Concentration of calcium in a sample may be determined by precipitation using the chromate ion, Crom-. Ca2+ (aq) + Cro - (aq) — CaCro,(s)
A chemist combined 0.180 L of an unknown calcium solution with an excess of ammounium chromate. This resulted in the
precipitation of calcium chromate. The mass of the precipitate was 282.7 mg. What was the molar concentration of Ca2+ in the
original sample?
[Ca2+] =? M

If soap hits the floor, is the soap dirty or the floor

Problem #3 (ch. 1, problem 15)the ideal gas law provides one way to estimate the pressure exerted by a gas on a container. the law isí‘ťí‘ť=푛푛푛푛푛푛푉푉mo re accurate estimates can be made with the van der waals equationí‘ťí‘ť=í‘›í‘›í‘›í‘›í‘›í‘›í‘ ‰í‘‰â’푛푛푟푟â’푞푞푛푛2í‘ ‰í‘‰2where the term nb is a correction for the volume of the molecules and the term an2/v2is a correction for molecular attractions. the values of a and b depend on the type of gas. the gas constant is r, the absolutetemperature is t, the gas volume is v, and the number of moles of gas molecules is indicated by n. if n = 1 mol of an ideal gas were confined to a volume of v = 22.41 l at a temperature of 0â°c (273.2k), it would exert a pressure of 1 atm. in these units, r = 0.0826.for chlorine gas (cl2), a = 6.49 and b = 0.0562. compare the pressure estimates given by the ideal gas law and the van der waals equation for 1 mol of cl2 in 22.41 l at 273.2 k. what is the main cause of the difference in the two pressure estimates, the molecular volume or the molecular attractions?

Which rate indicates the number of children that would be born per woman if she were to live to the end of her child bearing years