This is the content of the pop-over!
  
Exam Edge Dark Logo Exam Edge Dark Logo
Business
Healthcare
Education
World


Recent Searches
Try searching for



Praxis Middle School Science (5440) Practice Tests & Test Prep by Exam Edge - Free Test


Our free Praxis Middle School Science (5440) Practice Test was created by experienced educators who designed them to align with the official Educational Testing Service content guidelines. They were built to accurately mirror the real exam's structure, coverage of topics, difficulty, and types of questions.

Upon completing your free practice test, it will be instantly reviewed to give you an idea of your score and potential performance on the actual test. Carefully study your feedback to each question to assess whether your responses were correct or incorrect. This is an effective way to highlight your strengths and weaknesses across different content areas, guiding you on where to concentrate your study efforts for improvement on future tests. Our detailed explanations will provide the information you need to enhance your understanding of the exam content and help you build your knowledge base leading you to better test results.

Login or Create an Account to take a free test

After you have completed your free test you will receive a special promo code that will save your between 15-20% on any additional practice tests!

Get Instant Online Access Now!

** Sample images, content may not apply to your exam **

Praxis Middle School Science (5440) Shortcuts

Additional test information
General Exam Info
Exam Topics
Exam Topics
Features
Features
Study Plan
Study Plan Tips
Exam Edge Desc
Test Reviews
Why Exam
Why Exam Edge?
Exam FAQ
FAQ
Exam Related Blogs
Related Blogs
Exam FAQ
FREE Practice Test

Praxis Middle School Science - Free Test Sample Questions

Identify the ingredient commonly used in antibacterial soaps.

Correct Answer:
chloroxylenol


loroxylenol. this chemical compound is frequently used as an active ingredient in antibacterial soaps and other disinfectants. chloroxylenol is known for its ability to effectively eliminate a broad spectrum of bacteria, making it a popular choice in settings that require stringent hygiene practices, such as hospitals and kitchens.

chemically, chloroxylenol is an aromatic compound that is derived from phenol. it includes a chlorine atom in its molecular structure, which is pivotal for its antimicrobial properties. the presence of chlorine helps in disrupting the cell walls of bacteria, thereby leading to their destruction. this action not only stops the growth of bacteria but also prevents the transmission of bacteria from one surface to another, ensuring a cleaner and more hygienic environment.

the widespread use of chloroxylenol in antibacterial products underscores its effectiveness and reliability. by targeting a variety of bacteria, it plays a crucial role in controlling infections and maintaining public health. although it is powerful against bacteria, chloroxylenol is also noted for being relatively safe for human use, which is why it is a preferred ingredient in many consumer products aimed at reducing bacterial contamination.

Which gases will not apply to Dalton’s Law of partial pressure?

Correct Answer:
nitric oxide and oxygen


dalton's law of partial pressures states that in a mixture of non-reacting gases, the total pressure exerted is equal to the sum of the partial pressures of the individual gases. this law is applicable under the assumption that the gases do not interact chemically with each other. the partial pressure of each gas is the pressure that it would exert if it occupied the entire volume of the mixture alone at the same temperature.

however, when gases react chemically, dalton’s law does not hold. this is because chemical reactions change the identity and the number of moles of the gases involved, thus affecting the pressures they exert. a notable example of such a scenario is the reaction between nitric oxide (no) and oxygen (o2), which can be represented by the chemical equation: \[ \text{2no} + \text{o}_2 \rightarrow \text{2no}_2 \] in this reaction, nitric oxide and oxygen combine to form nitrogen dioxide (no2), which is a different chemical entity with different properties, including different behavior under the same conditions of temperature and pressure.

in the specific case of nitric oxide and oxygen, initially, the partial pressures of these gases would contribute to the total pressure in the container. however, as they react to form nitrogen dioxide, the number of moles of the gases changes, and nitrogen dioxide might exert a different pressure compared to the sum of the partial pressures of nitric oxide and oxygen if they had not reacted. therefore, the total pressure in the container would not merely be the sum of the initial partial pressures as dalton’s law would predict.

thus, for mixtures involving chemical reactions such as nitric oxide and oxygen reacting to form nitrogen dioxide, dalton's law of partial pressures does not apply. this demonstrates the importance of considering chemical reactivity when predicting the behavior of gas mixtures under various conditions.