In what sense can a transformer be considered an electrical lever? What does it multiply? What does it not multiply?

This is because it steps up or steps down electrical voltage. It multiplies either voltage (if it is a voltage transformer )or current (if it is a current transformer), but it does not multiply electrical power.

Explanation:

A transformer steps up or steps down electrical voltage, by transmitting power at a voltage, V₁ and Current I₁ at one terminal, to a voltage, V₂ and Current I₂ at its other terminals, just like a lever transmits force from one point to another. Since the power transmitted remains the same, (energy per unit time remains constant), I₁V₁ = I₂V₂ ⇒ I₁/I₂ = V₂/V₁ = n (the turns ratio of the transformer). So, the turns ratio will determine if its a step-up or step-down transformer. V₂ = nV₁. So, if V₁ > V₂ it is a step down transformer and if V₁ < V₂ it is a step-up transformer.It multiplies either voltage (if it is a voltage transformer )or current (if it is a current transformer), but it does not multiply electrical power, since P = IV = constant for the transformer.

  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