6. How many grams are in 3.45 x1022 molecules of Na2CO3? 7. How many moles are in 26.88g of KCI?

8. How many moles are in 0.02345 g of NH4C2H302?

9. How many grams are in 8.64x1025 molecules of KCI?

10. How many moles are in 3.45 g of Pb(Cr2O7) ?

11. How many molecules are in 0.00487 g of KCI?

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

Δu of , in kj/kg, as it isto k, (a)as a of , (b) at , (c) at .

What is the indicator of the number of ions in solution? the amount of conductivity the amount of precipitate the amount of solute added