10618 G of an Unknown Salt Is Dissolved in a Coffee

question 2

Multiple Choice

10.618 g of an unknown salt is dissolved in a coffee cup calorimeter that contains 50.0 mL of water.The measured temperature decreased from 23.8 °C to 22.7 °C.Identify the unknown salt.The specific heat of water is 4.184 J g^-1 °C^-1,and assume the density of the solution is 1.00 g mL^-1.

• A)NaF, \(D _ { \mathrm { r } }\) H = 0.91 kJ mol^-1
• B)NaBr, \(D _ { \mathrm { r } }\) H = -0.60 kJ mol^-1
• C)NaNO₃, \(D _ { \mathrm { r } }\) H = 20.50 kJ mol^-1
• D)LiNO₃, \(D _ { \mathrm { r } }\) H = -2.51 kJ mol^-1
• E)LiBr?2H₂O, \(D _ { \mathrm { r } }\) H = -23.26 kJ mol^-1

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Definitions:

Digital Signal

An electronic signal that represents data as a series of discrete values, typically used in digital electronics and communication.

DC

Direct Current, a type of electrical current where the flow of electric charge is in a constant direction, contrasted with alternating current (AC).

AC

Alternating Current, a type of electrical current in which the flow of electric charge periodically reverses direction.

XIC Instruction

In ladder logic and PLC programming, the "Examine if Closed" instruction that checks if a particular condition is true (i.e., if a contact is closed).