A rock dropped in a graduated cylinder raises the level of water from 20 mL to 35 mL. The rock has a mass of 45 g. What is the density of the rock?

There are 6.022 x 10^23 atoms of hg in 1 mole of hg. the number of atoms in 4.5 moles of hg can be found by multiplying 4.5 by 6.022 x 10^23 a. 2.7 x 10^24 b. 27 x 10^23 c. 2.71 x10^24 d. 27.099 x 10^23

In a spacecraft, the following reaction occurs: co2(g) + 2lioh(s) -> lico3(s) + h2o(i) (i attached picture of equation) how many liters of carbon dioxide will 4 moles of lithium hydroxide (lioh) absorb? (one mole of any gads occupies 22.4 l under certain conditions of temperature and pressure. assume those conditions for this equation.) 45l 6.0l 3.0l 34l

How many moles is 14.5 cm^3 of platinum? the density of platinum is 21.45 g/cm^3.