Chapter 2, Problem 2.69E

You have two distinct gaseous compounds made from element X and element Y. The mass percents are as follows: Compound I: 30.43% X, 69.57% Y Compound II: 63.64% X, 36.36% Y In their natural standard states, element X and element Y exist as gases. (Monatomic? Diatomic? Triatomic? That is for you to determine.) When you react gas X with gas Y to make the products, you get the following data (all at the same pressure and temperature): 1. volume gas X + 2 volumes gas Y2 volumes compound I 2. volumes gas X + 1 volume gas Y2 volumes compound II Assume the simplest possible formulas for reactants and products in the chemical equations above. Then, determine the relative atomic masses of element X and element Y.

7. Each of the following statements about the properties of matter are false. Choose two statements and explain the fallacy. a. Aluminum conducts electricity because it allows electrons to flow between covalent bonds between atoms in the crystal lattice. b. The bonding within H,O molecules explains why water has a high boiling point. с. The geometry of an ionic compound determines if it's polar or non-polar.

Correct the following statements.a. An element is a combination of two or more compounds.b. When a small amount of sugar is completely dissolved in water, a heterogeneous solution is formed.

2. Which of the following mixtures can be separated by handpicking? * A. solution B. homogeneous C. heterogeneous D. both B and C 3. In your drawer, several solids like thumbtacks, paper clips and pieces of papers are scattered. How will you separate the thumbtacks and paper clips from the pieces of papers? * ) A by handpicking () B. by magnetizing () C. by decantation () D. both A and B 4. Which of the following cannot be separated by magnetizing? * ( A. pebbles and paper ( B. pebbles and paper clips () C. pebbles and staple wires () D. water and pieces of iron

ww TTTTT #1 #2 Use the pictures above to answer questions 12 & 13. 12 Which picture or pictures best show a pure element? A. Picture #1 & Picture #2 B. Picture #1 only 13 Which picture shows a pure compound? #1 & Picture #2 #3 A. B. Picture #1 only C. Picture #3 & Picture #4 D. Picture #4 only C. Picture #3 & Picture #4 D. Picture #4 only #4 14 Which is NOT a characteristic of a solid? A. Fixed shape and fixed volume. B. Atoms or molecules very closely packed together in a regular arrangement. C. The atoms or molecules vibrate at different rates at different temperatures. D. The free surface is a gravity surface, and always horizontal to the Earth's surface. What is a solid substance in which the atoms and molecules are in a repeating 3- 15 dimensional arrangement or bonding pattern throughout? A. Crystalline solids B. Amorphous solids C. Ambidextrous solids D. Marl solids What is a solid substance in which the atoms and molecules are randomly or 16 inconsistently arranged throughout?…

A What I have learned? Answer the following questions. 1. Can a physical change occur even if there is no chemical change? and vice versa? 2. Is it possible that two things that have identical physical properties will have different chemical property? Give an example. 3. In any reactions, which is more reliable to give accurate measurement, physical or chemical property? 4. What is the difference between elements and compounds? Give example of each. 5. How do a molecule and a compound differ? 6. Are all compound can be molecules? How about vice versa? Why or why not? 7. Does a physical appearance of the product affect its chemical quality? How about vice versa? 8 When can each method be used in separating the components of a mixture? 1.

A substance composed of 2 or more elements in a fixed, definite proportion is considered a homogeneous mixture. a heterogeneous mixture. a molecular compound an alloy. a solution.

Which statement is incorrect?  A. All molecules are compounds but not all compounds are molecules. (Semua molekul adalah sebatian tetapi tidak semua sebatian adalah molekul.) B. A molecule is formed when two or more atoms join together chemically. (Molekul dibentuk apabila dua atau lebih atom bergabung bersama secara chemical.) C. A compound is a molecule that contains at least two different elements. (Sebatian adalah molekul yang mengandungi sekurang-kurangkan dua unsur yang berbeza) D. All compounds are molecules but not all molecules are compounds. (Semua sebatian adalah molekul tetapi tidak semua molekul adalah sebatian.)

Use the information and models to answer the following question. A group of students are trying to design an electrical material. The models are options of substances that the students could use. Model A Model B Model C Methane (CH4) Electrons Positive lon Negative lon Positive ions Which substances should the students use if they are trying to design an electrically conductive material? O A. Models A, B, and C because all compounds can conduct electricity. O B. Models B and C because gases and metals can conduct electricity. O C. Models A and C because they contain ions so they can conduct electricity. O D. Models A and B because the majority of materials on Earth are made of these.