Two Solutions (The System),each with a Volume of 25

question 120

Multiple Choice

Two solutions (the system) ,each with a volume of 25.0 mL at 25.0°C,are mixed in a beaker.A reaction occurs between them,and the temperature rises to 35.0°C.After the products have equilibrated with the surroundings,the temperature is again 25.0°C and the total volume is 50.0 mL.No gases are involved in the reaction.Which relationship concerning the change from initial to final states (both at 25.0°C) is correct?

• A)ΔU = 0
• B)ΔH = 0
• C)ΔU > 0
• D)q = 0
• E)W = 0

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Definitions:

Placebo Effect

A phenomenon where a person experiences a perceived improvement in condition due to their expectations, rather than the effect of an active intervention.

Placebo Effect

A psychological phenomenon where patients experience perceived or actual improvements in their condition due to their belief in the efficacy of a treatment that is inert or not specifically effective for the condition being treated.

Fake Treatment

A placebo or sham treatment, with no therapeutic effect, used as a control in testing new drugs or treatments.

Control Group

In experimental research, a group of subjects that does not receive the treatment being tested, used as a benchmark to measure the effect of the treatment on another group.