How many atoms in 15ZnSO4

90

Explanation:

To find the number of atoms in a formula, you have to add the number of each element. To find the number of each element, multiply the coefficient by the subscript for each individual element. If an element does not have a subscript, it is equal to 1.

Zn = 15x1 = 15

S = 15x1 = 15

O = 15x4 = 60

60+15+15 = 90 atoms.

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.