Mercury(II) oxide breaks down on heating: 2 HgO (s)-2Hg (1) + O2(g)
a Calculate the mass of 1 mole of mercury(II)
oxide. (A: 0 = 16, Hg = 201)
b How much mercury and oxygen could be
obtained from 21.7 g of mercury(II) oxide?
c Only 19.0 g of mercury was collected. Calculate
the % yield of mercury for this experiment.

State two physical properties of ionic compound

Agroup of students is studying convection current. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other is in an area with warm air. after 10 minutes, the balloon are released from a height of 1 meter. which of the following to the students most likely observe? a) the warm balloon expands and rises. the cold balloon shrinks and sinks b) the balloon both rise. the cold balloon is larger than the warm balloon c) the cold balloon expands and rises. the warm balloon shrinks and sinks d) the balloon rise at the same rate. both balloons are the same size

Given the following at 25c calculate delta hf for hcn (g) at 25c. 2nh3 (g) +3o2 (g) + 2ch4 (g) > 2hcn (g) + 6h2o (g) delta h rxn= -870.8 kj. delta hf=-80.3 kj/mol for nh3 (g), -74.6 kj/mol for ch4, and -241.8 kj/mol for h2o (g)