The percent by mass of Ca in CaCl2 is equal to 1. (40/111) x 100
2. (111/40) x 100
3. (3/1) x 100
4. (1/3) x 100

Agas mixture with a total pressure of 745 mmhg contains each of the following gases at the indicated partial pressures: co2, 245 mmhg ; ar, 119 mmhg ; and o2, 163 mmhg . the mixture also contains helium gas. part a what is the partial pressure of the helium gas? phe p h e = nothing mmhg request answer part b what mass of helium gas is present in a 10.2-l sample of this mixture at 283 k ? m m = nothing g request answer

Which of the following is not a true statement about dwarf planets? a the kuiper belt contains comets, asteroids, and dwarf planets. b ceres is a dwarf planet located in the kuiper belt. c the largest known dwarf planet in the solar system is named eris.

Astudent pours 10.0 g of salt into a container of water and observes the amount of time it takes for the salt to dissolve. she then repeats the process using the same amounts of salt and water but this time she slowly stirs the mixture while it is dissolving. the student performs the experiment one more time but this time she stirs the mixture rapidly. the dependent variable in this experiment is: time for salt to dissolve speed of stirring amount of water mass of salt