Scientist discover that stars in the universe are mostly composed of which elements?

Achemistry student weighs out of phosphoric acid , a triprotic acid, into a volumetric flask and dilutes to the mark with distilled water. he plans to titrate the acid with solution. calculate the volume of solution the student will need to add to reach the final equivalence point. round your answer to significant digits.

As you watch a surfer ride a wave towards the shoreline, what is the shoreline? a) displacement reference b) reference point c) coordinate plane d) cartesian boundary

1) which of the following is the best example of a physical change? a) sugar dissolving in tea b) firefly glowing 2) in the combustion of ethane, what is/are the reactants? c2h6 + o2 ==> co2 + h2o a) c2h6 and o2 b) co2 and c2h6