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.

The correct answer is option C, that is, the warm balloon expands and rises, and the cold balloon shrinks and sinks.

It is known from the ideal gas equation, that PV = nRT

Here, P is pressure, V is volume, n is the number of atoms in gas, R is gas constant, and T is temperature.

From the equation, it is clear that the volume of balloon is directly proportional to the temperature. It signifies that at constant pressure when temperature elevates than at that time volume of the balloon will increase and when temperature reduces the volume of balloon will decrease.

Thus, the volume of warm balloon will increase because of which its density increases and it can rises easily as a less dense substance can easily rises in air in comparison to more dense gas or substance. Thus, the cold balloon shrinks and sinks.

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g

i think its 5049.

i hope this !