Q: A student is asked to calculate the energy change ($$q) $$when 50 g of water is heated from $$25^\circ C to$$ $$75^\circ C. $$The specific heat of water is $$4.18 \frac{J}{g \cdot ^\circ C}. $$Which formula should be used?

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

Question 1

Which of the following best describes the main focus of General Chemistry I as outlined in the course description?

Accepted Answer

It introduces fundamental concepts such as atomic structure, stoichiometry, chemical bonding, and the physical behavior of gases.

Question 2

A student is asked to calculate the number of moles in 18 grams of water ($$H_2O). $$What is the correct calculation?

Accepted Answer

$$\frac{18}{18}$$

Question 3

Which equation would you use to convert temperature from Celsius to Kelvin, as required in thermochemistry calculations?

Accepted Answer

$$K = ^\circ C + 273$$

Question 4

During a laboratory experiment, a student measures the mass of a gas and its volume at standard temperature and pressure (STP). Which law should the student use to relate these quantities?

Accepted Answer

Ideal Gas Law: $$PV = nRT$$

Question 5

Which of the following is the correct electron configuration for a neutral oxygen atom?

Accepted Answer

$$1s^2$$ $$2s^2$$ $$2p^4$$

Question 6

A student mixes solutions of $$NaCl$$ and $$AgNO_3 in a $$laboratory experiment. What type of reaction occurs, and what is the precipitate formed?

Accepted Answer

Double displacement; $$AgCl$$

Question 7

Which of the following statements about Avogadro's number is correct?

Accepted Answer

It is the number of molecules in one mole of a substance.

Question 8

A student is asked to balance the following chemical equation: $$C_2H_6 + O_2$ \rightarrow CO_2$ + H_2O. $$What is the correct set of coefficients?

Accepted Answer

$$2, 7, 4, 6$$

Question 9

Which formula is used to calculate the molarity ($$M) of a $$solution?

Accepted Answer

$$M = \frac{moles\ of\ solute}{volume\ of\ solution\ (L)}$$

Question 10

Which of the following best explains why noble gases are generally unreactive?

Accepted Answer

They have completely filled valence electron shells.

Question 11

A student is asked to determine the limiting reactant in a reaction between 5.0 g of $$Al$$ and 10.0 g of $$O_2 to $$produce $$Al_2O_3. $$Which steps should the student follow?

Accepted Answer

Convert grams of each reactant to moles, use stoichiometry to find which produces less $$Al_2O_3.$$

Question 12

Which of the following is the correct formula for calculating the density ($$d) of a $$substance?

Accepted Answer

$$d = \frac{mass}{volume}$$

Question 13

Which statement best describes the difference between ionic and covalent bonding?

Accepted Answer

Ionic bonds involve the transfer of electrons; covalent bonds involve the sharing of electrons.

Question 14

Which of the following is a correct application of the periodic law?

Accepted Answer

Elements are arranged in order of increasing atomic number.

Question 15

A student is asked to predict the molecular geometry of $$CH_4$$ using VSEPR theory. What is the correct geometry?

Accepted Answer

Tetrahedral

Question 16

Which of the following is the correct balanced equation for the reaction of hydrochloric acid with sodium hydroxide?

Accepted Answer

$$HCl + NaOH \rightarrow NaCl + H_2O$$

Question 17

A student is asked to calculate the energy change ($$q) $$when 50 g of water is heated from $$25^\circ C to$$ $$75^\circ C. $$The specific heat of water is $$4.18 \frac{J}{g \cdot ^\circ C}. $$Which formula should be used?

Accepted Answer

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

Question 18

Which laboratory safety practice is mandatory before beginning any experiment, as outlined in the course policies?

Accepted Answer

Wearing approved lab safety goggles.

Question 19

A student is asked to explain the difference between an element and a compound. Which statement is correct?

Accepted Answer

An element consists of only one type of atom, while a compound consists of two or more types of atoms chemically bonded.

CHEM-105 Principles of General Chemistry I: Syllabus and Study Guide

Guida di studio - Domande di pratica

Study guide - Flashcard