What is [OH-]? Please include work so I know how to answer future questions. Thanks! :)

Calculate the molar mass of aluminum oxide (al2o3). express your answer to four significant figures.

Significant figures are digits read directly from the measuring instrument plus one more digit, which is __ by the observer.

Each of the following reactions is allowed to come to equilibrium and then the volume is changed as indicated. predict the effect (shift right, shift left, or no effect) of the indicated volume change. drag the appropriate items to their respective bins.co(g) + h2o(g) < => co2(g) + h2(g) (volume is decreased) pcl3(g) + cl2(g) < => pcl5(g) (volume is increased) caco3(s)< => cao(s) + co2(g) (volume is increased)