Why do scientific experiments need to be repeated? A. Because scientists often make mistakes

B. To ensure that the same results are achieved every time

C. They only need to be repeated if the results are questionable

D. To discourage other scientists from trying to get the same results

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.