You jog at 9.85 km/h for 8.10 km, then you jump into a car and drive an additional 16.2 km. with what average speed must you drive your car if your average speed for the entire 24.3 km is to be 21.0 km/h?

Average speed = Distance traveled / time taken

In jogging case Time taken = distance/speed

                                        = 8.10/9.85 = 0.8223 hours

In care case Time taken = distance/speed

                                        = 16.2/v  hours

So total time taken , t = 0.8223+16.2/v

Total distance traveled = 8.10 km + 16.2 km = 24.30 km

So average speed

Average speed you must drive your car if your average speed for the entire 24.3 km is to be 21.0 km/h = 48.38 km/hr

  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