What can you use to test substancea for their ph value if you dont have a strip of litmus paper handy?

In the first law of thermodynamics, triangle e=q-w, what does q stand for

Global warming will produce rising sea levels partly due to melting ice caps but also due to the expansion of water as average ocean temperatures rise. to get some idea of the size of this effect, calculate the change in length of a column of water 1.00 km high for a temperature increase of 1.00ºc. note that this calculation is only approximate because ocean warming is not uniform with depth. (answer in ×10^{-3} −3 m)

How many atoms of nitrogen are in the chemical formula ni(w on