2HgO(s) + 90.8 kJ → → Hgw + O2(g) In the equation above, how many kilojoules of heat are needed to react with 1.00 mole of HgO(s)?

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?   %

Which statement best describes isomers? a. isomers are alcohols that have the same functional group. b. isomers have at least one carbon-carbon double bond. c. isomers have the same molecular formula but different structural properties.

What the blanks in these lines are ?