Question

How many grams of ZNO shoulbe added to 30gms of 10%ZNO to get 15%oint​

Answer 1

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 :

`\tt (3+x)/(30+x)=15\%\\\\15\%(30+x)=3+x\\\\4.5+0.15x=3+x\\\\1.5=0.85x\\\\x=1.765~gms`