Q: Which equation is used to calculate the heat absorbed by water in a calorimeter?

$$q = m \times c \times \Delta T$$

Question 1

Which of the following best describes the First Law of Thermodynamics?

Accepted Answer

Energy can be converted from one form to another, but it cannot be created or destroyed.

Question 2

A chemical reaction occurs in a closed system. Which of the following statements is TRUE?

Accepted Answer

The system can exchange heat but not mass with its surroundings.

Question 3

Which equation correctly represents the kinetic energy of an object?

Accepted Answer

$$E_k = \frac{1}{2}mv^2$

Question 4

A system absorbs heat from its surroundings and does work on the surroundings. Which sign convention correctly describes the values of $$q$$ and $$w$$?

Accepted Answer

$$q \u003e 0$$, $$w \u003c 0$$

Question 5

Which of the following is a state function?

Accepted Answer

Internal energy ($$E)$$

Question 6

Which process is described as endothermic?

Accepted Answer

The system absorbs heat from the surroundings.

Question 7

What is the mathematical expression for work done by a force over a distance?

Accepted Answer

$$w = F 	imes d$$

Question 8

Which statement about enthalpy ($$H) is $$correct?

Accepted Answer

Enthalpy is a state function and depends only on the current state of the system.

Question 9

If a reaction is carried out in a series of steps, which law allows you to sum the enthalpy changes of each step to find the overall enthalpy change?

Accepted Answer

Hess's Law

Question 10

Which equation represents the change in internal energy of a system?

Accepted Answer

$$\Delta E = q + w$$

Question 11

A reaction in a bomb calorimeter occurs at constant volume. What is measured directly?

Accepted Answer

Change in internal energy ($$\Delta E)$$

Question 12

Which of the following statements about bond enthalpy is TRUE?

Accepted Answer

Bond enthalpy is always positive because energy is required to break bonds.

Question 13

Which equation is used to calculate the heat absorbed by water in a calorimeter?

Accepted Answer

$$q = m 	imes c 	imes \Delta T$$

Question 14

Which of the following is TRUE about the enthalpy of formation ($$\Delta H_f^\circ) $$for an element in its standard state?

Accepted Answer

It is zero by definition.

Question 15

A chemical reaction has $$\Delta H = -250 kJ. $$Which statement is correct?

Accepted Answer

The reaction is exothermic and releases heat.

Question 16

Which of the following best describes an isolated system?

Accepted Answer

It cannot exchange heat or mass with its surroundings.

Question 17

Which property is extensive and depends on the amount of substance present?

Accepted Answer

Enthalpy ($$H)$$

Question 18

In a real-world scenario, why is the enthalpy change for a reaction dependent on the physical states of reactants and products?

Accepted Answer

Because different states have different enthalpy values due to intermolecular forces.

Question 19

Which of the following is NOT a correct application of Hess’s Law?

Accepted Answer

Using the path taken by the reaction to determine enthalpy change.

Thermochemistry: Energy, Enthalpy, and Heat in Chemical Reactions

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