1. Mrs. Johnson’s first period class is designing an investigation to determine what could affect the rate of chemical change when vinegar is added to baking soda. Which of the following would be a valid test (independent) variable for this experiment? A. The Temperature of the vinegar at the start of the reaction.
B. The time it takes for the reaction to take place.
C. The amount of gas produced by the reaction
D. The color of the products of the reaction.

Liquid ammonia is produced at high temperatures and under great pressure in a tank by passing a mixture of nitrogen gas and hydrogen gas over an iron catalyst. the reaction is represented by the following equation. n2(g) + 3h2(g) → 2nh3(g) changing all but one experimental condition will affect the amount of ammonia produced. that condition is a) increasing the concentration of both reactants b) changing the temperature within the tank c) decreasing the pressure within the tank. d) increasing only the amount of nitrogen present.