Which of the following equations is not balanced? n2 + 3h2 → 2nh3 a. n2 + 3h2 → 2nh3 b. mgi2 + br2 → mgbr2 + i2 c. kclo3 → kcl + o2 d.hcl + naoh → nacl + h2o

(C) is correct option

Explanation:

Balanced equation :

In balanced equation, The number of atoms of each element in product side equal to the number of atoms of each element in reactant side.

The equation is not balanced in option C.

In this equation, The number of oxygen element in product side is not equal to the number of oxygen element in reactant side.

All equations are balanced.

1.98s

Explanation:

The time taken to hit the ground is given by

h=ut+ 1/2 at^2

but u =0

so we have

h=1/2at^2

making t the subject

t=√2h/g

√2×19.6/10

1.98s