Air in a balloon does 40 J of work expanding the balloon while absorbing 60 J of heat. What is the change in internal energy

DU = 20 Joules

Explanation:

Given the following data;

Heat absorbed, Q = 60J

Workdone, W = 40J

To find the internal energy;

We would use first law of thermodynamics given by the formula;

Change in internal energy (DU) = Q - W

where;

U is internal energy.

Q is the heat absorbed.

W is the work done.

Substituting into the equation, we have;

DU = 60 - 40

DU = 20 Joules

  the grams     of oxygen gas   that can be produced     is 20.6   grams of o₂

calculation

2liclo₃ →   2 licl + 3 o₂

step 1:   find the moles of liclo₃

moles = mass÷ molar mass

from periodic table the molar mass of liclo₃ =6.9 +35.5   +(16 x3) =90.4 g/mol

moles=38.7 g÷90.4 g/mol=0.4281   moles

step 2:   use the   mole ratio   to calculate the moles of o2

from equation above, liclo₃: o₂   is 2: 3  

therefore the moles of   o₂=0.4281 moles x3/2 =0.6422   moles

step 3: find mass   of o₂

mass= moles x molar mass

from periodic table the   molar mass of   o₂ = 16 x2= 32 g/mol

mass=0.6422   moles   x   32 g/mol = 20.6 grams of o₂