Chemistry Texas Test

Carla used an indicator strip to measure the pH of a basic solution. She then slowly added 50 mL of an acidic solution into the basic solution and gently stirred them together. She placed a drop of the new solution onto an indicator strip and measured its pH. Which of the following statements describes how the pH could have changed?

• the pH changed from 1 to 7

• the pH changed from 6 to 2

• the pH changed from 8 to 13

• the pH changed from 10 to 7

Tags

NGSS.MS-PS1-2

Nathan spills an unknown liquid. While wearing protective gloves, he cleans up the spill and notices that the liquid feels slippery. Which substance is the unknown liquid most like?

• a salt

• a base

• an acid

• a neutral substance

Acid reflux occurs when acid from a person’s stomach escapes from the stomach and enters the esophagus, a flexible tube that leads into the stomach. Which substance would be best for neutralizing stomach acid?

• a substance with a pH of 1

• a substance with a pH of 5

• a substance with a pH of 9

• a substance with a pH of 7

Which of the following substances is the strongest acid?

• lemon juice – pH 2

• orange juice - pH 4

• bleach – pH 12.5

• oven cleaner – pH 13

1. A student uses a pH indicator to determine the pH of three solutions. The results from the tests are in the table.

Solution pH

Ammonia 12.0

Lemon juice 2.5

Distilled water 7.0

Which list shows the solutions from least basic to most basic

• lemon juice, distilled water, ammonia

• lemon juice, ammonia, distilled water

• distilled water, lemon juice, ammonia

• distilled water, lemon juice, ammonia

Which statement correctly describes the structure of an atom?

• It has a nucleus in which electrons orbit neutrons and protons orbit electrons

• It has a nucleus containing electrons and neutrons, with protons orbiting around the nucleus

• It has a nucleus containing protons and neutrons, with electrons orbiting around the nucleus

• It has no nucleus. Protons, neutrons, and electrons all orbit each other and follow no formal pattern

The Rutherford-Bohr model of the atom was the first really useful model that accurately illustrated what scientists knew of the behavior of atoms in the early 1900s. Based on today’s understanding of atoms, what must an accurate, useful model of an atom contain?

• protons, neutrons, electrons

• hydrogen, oxygen, potassium

• molecules, bonds, compounds

• ions, alpha particles, gamma rays

Tags

NGSS.MS-PS1-1

Many scientists have contributed to the atomic theory. In 1803 John Dalton gave new insight to this theory. Which description of an atom fits our most current understanding?

• Every oxygen atom is the same as every hydrogen atom

• Every hydrogen atom is the same as every other hydrogen atom

• Every atom of water is the same as any atom of another liquid

• Every atom of one solid is the same as any atom of another solid

A model of a nitrogen atom is shown here.

In this model, what do the black spheres represent?

• electrons

• neutrons

• photons

• protons

Tags

NGSS.MS-PS1-1

If a sample of gold were reduced to the smallest possible particle of pure gold, which statement would most accurately describe the result?

• The sample would be reduced to atoms of gold

• The sample would be reduced to molecules of gold

• The sample would be reduced to protons and neutrons of gold

• The sample would be reduced to electrons and protons of gold

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-5