Question

Let |⃗A₁| = 3, |⃗A₂| = 5, and |⃗A₁ + ⃗A₂| = 5. The value of |2⃗A₁ + 3⃗A₂| . (3⃗A₁ – 2⃗A₂)
is :
(A) –106.5 (B) –112.5
(C) –118.5 (D) –99.5

Answer 1

Thus the atomic cadmium is 106.5

Explanation:

Question statement:

1.5 g of CdCl2 was found to contain 0.9 g of Cd  ?

Solution:

Mass of CdCl = 1.5 g

mass of Cd = 0.9 g

Now from stochiometry;

CdCl2 ----> Cd + 2Cl

Let the atomic weight of Cd = x

Now the moles of CdCl = moles of Cd = moles of Cl/2

(Given mass / At. weight)CdCl = (Given mass / At.weight)Cd

1.5 / x + 71 = 0.9 / x

1.5 x = 0.9 x + 0.9 x 71

x = 106.5

Thus the atomic cadmium is 106.5