Write a balanced equation for the combination reaction described, using the smallest possible integer coefficients.
1. When hydrogen combines with iodine , hydrogen iodide is formed.

H2 + I2 —> 2HI

Explanation:

H2 + I2 —> HI

Now, let us balance the equation. This can be achieved by doing the following:

There are 2 atoms of H on the left side of the equation and 1atom on the right side. It can be balance by putting 2 in front of HI as shown below:

H2 + I2 —> 2HI

Now the equation is balanced as there are equal numbers of atoms of the different elements present on both sides of the equation.

H2(g) + I2(g) → 2HI(g)

Explanation:

Step 1: Data given

hydrogen gas = H2(g)

iodine gas = I2(g)

hydrogen iodide = HI(g)

Step 2: The unbalanced equation

H2(g) + I2(g) → HI(g)

Step 3: Balancing the equation

On theleft side we have 2x H (in H2), On the right side we have 1x H (in HI)

To balance the amount of H on both sides we have to multiply HI on the right by 2

By multiplying HI by 2, the amount of O on both sides is also equal. The equation is balanced.

H2(g) + I2(g) → 2HI(g)