Q: A heating curve for water shows a flat line at $100\ ^\circ\mathrm{C}$. What is happening to the water at this temperature?

The water is boiling and undergoing a phase change from liquid to gas.

Q: Which of the following statements about the periodic table is correct?

Elements in the same group have the same number of valence electrons.

Question 1

Which of the following best describes a heterogeneous mixture?

Accepted Answer

A mixture in which the different components are not evenly distributed and can be visually distinguished.

Question 2

A student measures the mass of a sample as 12.30 g and the volume as 4.1 mL. What is the density of the sample, reported with the correct number of significant figures?

Accepted Answer

$3.0\ \mathrm{g/mL}$

Question 3

Which of the following is an example of a physical change?

Accepted Answer

Dissolving sugar in water.

Question 4

Which of the following statements about specific heat is correct?

Accepted Answer

Specific heat is the amount of heat required to raise the temperature of 1 gram of a substance by $1\ ^\circ\mathrm{C}$.

Question 5

A sample of water is heated from $25\ ^\circ\mathrm{C}$ to $75\ ^\circ\mathrm{C}$. If the mass of the water is $50.0\ \mathrm{g}$ and the specific heat of water is $4.18\ \mathrm{J/g\ ^\circ C}$, how much heat is absorbed?

Accepted Answer

$10,450\ \mathrm{J}$

Question 6

Which of the following correctly matches the phase change with its term?

Accepted Answer

Liquid to gas: vaporization

Question 7

Which of the following is the correct scientific notation for the number 0.000456?

Accepted Answer

$4.56 	imes 10^{-4}$

Question 8

A patient receives a medication at a dose of $2.5\ \mathrm{mg/kg}$ body weight. If the patient weighs $70.0\ \mathrm{kg}$, how many milligrams of medication should be administered?

Accepted Answer

$175\ \mathrm{mg}$

Question 9

Which of the following elements is an alkaline earth metal?

Accepted Answer

Magnesium

Question 10

How many protons, neutrons, and electrons are in the isotope $^{37}_{17}\mathrm{Cl}$?

Accepted Answer

17 protons, 20 neutrons, 17 electrons

Question 11

Which of the following best describes the difference between mass and weight?

Accepted Answer

Mass is the amount of matter in an object; weight is the force of gravity acting on that mass.

Question 12

Which of the following is the correct electron configuration for a neutral atom of sodium ($Z=11$)?

Accepted Answer

$1s^2\ 2s^2\ 2p^6\ 3s^1$

Question 13

A sample of a substance has a mass of $24.0\ \mathrm{g}$ and a volume of $8.0\ \mathrm{mL}$. What is its density?

Accepted Answer

$3.0\ \mathrm{g/mL}$

Question 14

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons.

Question 15

Which of the following best describes the process of condensation?

Accepted Answer

A gas changes to a liquid.

Question 16

If a metal has a specific heat of $0.385\ \mathrm{J/g\ ^\circ C}$, how much heat is required to raise the temperature of $25.0\ \mathrm{g}$ of the metal from $20.0\ ^\circ\mathrm{C}$ to $45.0\ ^\circ\mathrm{C}$?

Accepted Answer

$241\ \mathrm{J}$

Question 17

Which of the following is the correct order of increasing atomic radius for the elements: Na, Mg, Al?

Accepted Answer

Al < Mg < Na

Question 18

Which of the following is a chemical property?

Accepted Answer

Reactivity with acid

Question 19

A heating curve for water shows a flat line at $100\ ^\circ\mathrm{C}$. What is happening to the water at this temperature?

Accepted Answer

The water is boiling and undergoing a phase change from liquid to gas.

Question 20

Which of the following statements about the periodic table is correct?

Accepted Answer

Elements in the same group have the same number of valence electrons.

GOB Chemistry Exam 1 Review: Key Concepts and Study Guide

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Study Guide - Flashcards