Chemical substances that have a calming effect are known as: a. narcoticsb. hallucinogensc. depressantsd. stimulants

C) depressants are chemical substances that have a calming effect.

Depressants slow down the nervous system by using "calming" effects on your body. An example of a depressant is a tranquilizer, which is prescribed to help people lower their anxiety. Tranquilizers work by calming and relaxing the patient.

answer: the value of enthalpy change will be -152.80 kj.

solution:

pressure = 1atm , temperature = = 298 k

given that pressure and temperature are same in both gases , the number of moles of both gases can be determined by the ideal gas equation.

according to reaction 3 moles no are reacting with 1 mol of ,then 0.49 mol of no will react with moles of ozone that is 0.16 moles of ozone. since, no is limiting reagent and is an excessive reagent.

enthalpy change for the reaction between the given volumes of the gases is :