How many molecules are in 42.3g sample of water, H2O?

There are 14.152 molecules in 42.3 g sample of water, .

Explanation:

According to the mole concept, 1 mole of every substance contains atoms.

As mass of water (molar mass = 18 g/mol) is given as 42.3 g. Therefore, moles of water are as follows.

Hence, molecules of water are calculated as follows.

Thus, we can conclude that there are 14.152 molecules in 42.3 g sample of water, .

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

i do not get it   at all