What is the mass of 0.05 moles of potassium oxide, K2O?

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

How many moles of carbon dioxide will form if 2.5 moles of c3h8 is burned

In a water molecule, hydrogen and oxygen are held together by a(an) bond. a) double covalent b) ionic c) nonpolar covalent d) hydrogen e) polar covalent