Hi can someone please help me!

a) 2

b) 2

c) 5

d) 5

e) 5

Explanation:

a) There is 1 Ag atom and 1 Cl atom. When there's no subscript number next to an element, it means there is only one.

b) There is 1 Ca atom and 1 O atom.

c) There are 3 Mg atoms (there's a subscript 3 next to Mg) and 2 N atoms.

d) There are 2 Al atoms and 3 O atoms.

e) There are 2 Sc atoms and 3 S atoms.

 The  coefficient  for H2O  is  4

Explanation

Coefficient  is thew number  in front  of the formula in a  balanced chemical  equation.

The  balanced  equation as below

3H₂S  + 2HNO₃   →   3S  + 2 NO +4H₂O

The number in front of  H₂O  is  4  therefore   4  is the  coefficient for H₂O