How much speed is needed for an object to travel 250 km in 1.5 hrs? *
Your answer

166.67km/hr

Explanation:

Given the following :

Distance traveled = 250km

Time taken = 1.5 hours

Recall :

Speed = Distance traveled / time taken

Speed = 250 km / 1.5 hours

Speed = 166. 67 km/hr

Speed in m/s:

166.67km/hr = (166.67 × 1000)m / 3600 s

= 166670m / 3600s

= 46.3m/s

  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