PLEASE HELP I'M SO DOOMED A balloon that contains 2.8 mol of helium gas has a volume of 31 L. If 3.5 g of helium is added, what will be the new volume of the balloon? Assume the temperature and pressure remain the same. The molar mass of helium is 4.00 g/mol.
a) 186 L
b) 70 L
c) 24 L
d) 41 L
Do not post links

Which statement justifies that phosphine (ph3) is a polar molecule?

When determining the shape of a molecule, it is important to draw a lewis dot structure first in order to see the total number a. electrons within the moleculeb. bonding and unshared pairs around central atomc. unshared pair within the molecule( i really need it )

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.