Samuel adds a teaspoon of salt to a glass of water. he notices that the salt disappears. samuel takes a sip to discover that the water tastes salty. what kind of change has occurred?
a.
it’s a chemical reaction because a new substance has formed.
b.
it’s a physical change because the water and the salt kept their original properties.
c.
it’s an example of synthesis because two substances reacted to give one substance.
d.
it’s a chemical reaction because the water now tastes salty but originally did not.

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.