What mass of oxygen is required to completely react with 2 moles of ch4

The mass of oxygen that is required to react completely with 2 moles of CH4 is 128 grams

calculation

mass = moles xmolar mass

The molar mass of O2= 16 x2 = 32 g/mol

find the number of moles

first write the the equation for reaction

CH4 + 2O2 → CO2 + 2H2O

the mole ratio between CH4 to O2 is 1:2 therefore the moles of O2 = 2 x2 = 4 moles

mass is therefore = 32 g/mol x 4 moles = 128 grams

c. because step up transformer steps up the input voltage i.e increases the input voltage  

the number of turns are greater on the secondary side of step up transformer  

transformer does not handle dc current

the correct option is c.

isotopes refers to different forms of the same element with the same atomic number but different mass number as a result of difference in their neutron numbers. isotopes have different relative atomic mass but share the same chemical properties.