At 390 g of hot milk cools in a mug, it transfers 30,000 j of heat to the environment. what is the temperature change of the milk? the specific heat of milk is 3.9 j/g c. show work .

Answer

19.7°

Explanation

The quantity of heat is given by:

Q = mcΔt

where m is the mass, c is the specific heat capacity

Q = mcΔt

30,000 = 390/1000 × (3.9×1000) Δt

30,000 = 0.39 × 3900 × Δt

             = 1,521Δt

Δt = 30,000/1,521

    = 19.7°

  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