Equal amounts of gases A and B are placed in a closed reactor. A and B react to combine into AB in the following equilibrium reaction: A + B ⇌ AB Which are true about this system? Select two that apply. -A closed system allows for the transfer of energy in and out, so energy is not conserved in this system. -The total mass in the reactor gradually becomes zero because mass is consumed in closed systems. -The total mass in the reactor remains the same because products are removed from closed systems. -The total mass in the reactor remains the same because mass is conserved in closed systems.

c, liquids evaporate, creating a gas

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.

answer: any goods being imported from another country may be subject to issued by the federal government are tariffs

explanation:  

tariffs are a tax on anything that are imported from abroad. government use them to protect and boost their local industries and the thought is that they encourage consumers to buy local instead of importing and they will hope will protect jobs and economy in the country that implements them