Mass of ZnO added=1.765 g
Further explanation:
Given
30gms of 10%ZnO(Zinc oxide)
15% ZnO
Required
mass of ZnO added
Solution
Amount of ZnO in 30 gms of 10% ZnO =3 gms
For 15% ZnO : x= ZnO added
New solution = 30+x = 15%, so the equation :
[tex]\tt \dfrac{3+x}{30+x}=15\%\\\\15\%(30+x)=3+x\\\\4.5+0.15x=3+x\\\\1.5=0.85x\\\\x=1.765~gms[/tex]
