An inflatable toy starts with 1.05 moles of air and a volume of 5.17 liters. when fully inflated, the volume is 8.00 liters. if the pressure and temperature inside the toy don’t change, how many moles of air does the toy now contain?

-  1.62 moles

Solution:- At constant temperature and pressure, volume is directly proportional to the moles of the gas.

from given data, = 5.17 L, = 1.05 moles

= 8.00 L, = ?

Let's plug in the values in the formula:

On cross multiply:

= 1.62 moles

So, now the toy contains 1.62 moles of the air.

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.