C3H8(g)+ 5O2(g) 3C02(g) + 4H2O (g)

Which statement describes covalent bases? they have hydroxide ions. they produce hydrogen ions. they are often amines. they are named the same as ionic compounds.

How many moles of lead are in 1.50 x 10^12 atoms of lead? could you explain the answer as well and not just give it to me i am refreshing for finals and i need to know how to do it

Asample of tin (ii) chloride has a mass of 0.49 g. after heating, it has a mass of 0.41 g.  what is the percent by mass of water in the hydrate?   %