Why the copper ii sulphate and potassium oxalate solution must be stirred continuously in preparation of copper ii oxalete complex ?

Asample of the male sex hormone testosterone, c19h28o2, contains 3.88×10^21 atoms of hydrogen.(a) how many atoms of carbon does it contain? (b) how many molecules of testosterone does it contain? (c) how many moles of testosterone does it contain? (d) what is the mass of this sample in grams?

An atom of lithium-7 has an equal number of(1) electrons and neutrons(2) electrons and protons(3) positrons and neutrons(4) positrons and protons

If 22.5 liters of oxygen reacted with excess of hydrogen, how many liters of water vapor could be produced?