Study the reaction. 2HCl (g)+I2 (s)⇌2HI (g)+Cl2 (g)
When the reaction is at equilibrium, some amount of HI is added. The system then reaches equilibrium again.

How does the concentration of Cl2 change compare to the first equilibrium?

The concentration is higher.

The concentration is zero.

The concentration is the same.

The concentration is lower.

What shape would a molecule with two bound groups and two lone pairs have?

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)

Avariable that is not being directly tested during an experiment should be