Mastering Chemistry Chapter 1 Answer Key

When you need to be explicit, type * (Shift + 8) to insert the multiplication operator. You will see a multiplication dot (•) appear in the answer box. Do not use the symbol x.

For example, for the expression ma, typing m • a would be correct, but mxa would be incorrect. Enter the expression ma. ANSWER: ma = ma Correct When entering algebraic expressions, such as ma, you can enter it using explicit multiplication m • a or implied multiplication ma. Both will be accepted as correct.

All trigonometric functions assume angles are in radians by default, unless the use of degrees is specified. Part B Enter the expression 2cos 2 ( 6 ) — 1, where 6 is the lowercase Greek letter theta. ANSWER: 2cos 2 (6) — 1 = 2cos 2 ( 0 ) — 1 Correct To identify a variable displayed in a specific part, place your cursor over it. For instance, here is an example showing the Greek letter theta used in this problem . | theta| PartC Enter the expression asin(x) + 15, where asin(x) is the inverse sine function. ANSWER: c -\ asin(x) + 15 = asin(a^) + 15 V_/ Correct Use the same notation to enter other inverse trigonometric functions, for example acos(x) and atan(x) for the inverse cosine and tangent functions respectively.

Part D Enter the expression, where A is the uppercase Greek letter Delta. ANSWER: Correct Part E Enter the expression Noe~ xt , where Nq is N-naught (an N with a subscript zero) and A is the lowercase Greek letter lambda. ANSWER: N 0 e~ xt = N 0 e~ xt Correct Introduction to Drawing Lewis Structures This exercise is not intended to test your knowledge of any specific subject material.

Therefore, on this problem you will not be penalized for using hints or submitting incorrect answers. Overview When an assignment question requires that you answer by drawing molecules or species, you will see a canvas with buttons for bonds, electrons, charges, and atoms, such as the sample shown.

To specify types of bonds, click the bond button B on the left. Click a single bond to cycle through to double and triple bonds. to access the periodic table. The To specify atoms, select an atom from the menu at the bottom, or click the button with the word More carbon atom More is active by default. To draw atoms, ensure an atom button, such as To draw bonds, ensure the is highlighted in a blue outline and click anywhere within the grid area to create atoms. button is highlighted. You may draw a bond in one of two ways. You may click within the grid and drag your mouse to create two atoms connected with a bond. Or, if the atoms already exist in the grid, you can connect them with a bond by clicking on one of the atoms and dragging your mouse over to the second atom.

To place electron-dot pairs or single electrons, click 0 for a lone pair or for a single electron, and then click on an atom already in the workspace. You may then drag the pair of dots around the atom to change its orientation. To edit a charge associated with an atom, click V to increase the charge or 0 to decrease the charge, and then click on the atom. You should see a charge appear next to the atom. Click to change the charge sequentially, or type in the correct charge. • To select and move atoms or bonds, click and then click the atom or bond you wish to move. The atom or bond will turn green when selected. Then drag the atom or bond to a new location.

To deselect an atom or bond, click on an empty area of the grid. More and select the atom from the periodic table, or double-click on an existing atom and type the correct To add an uncommon element, click element symbol. To change the type of bond already drawn, click on the bond to rotate through single, double, and triple bonds. To delete a portion of the molecule or ion, click m and click the element you want to delete. j To undo, redo, or clear the canvas, click o o For help while drawing molecules and ions, click Grading Each question will specify whether lone pairs of electrons and charges are required. In general, you should draw all hydrogen atoms.

Although the molecule or ion you draw must contain the correct atoms and bond structure, the orientation of the molecule or ion is not graded. Try drawing a molecule upside down and you’ll see! Part A Draw the species sodium formate. The structure has been supplied here for you to copy r & Sodium formaie C ■ is – + H O: Na To add formal charges, click the 3 – – J or – J buttons below (which will have a blue outline when activated) before clicking on the species. Draw sodium formate by placing atoms on the grid and connecting them with bonds.

Include all lone-pair electrons. Hint 1. Step-by-step instructions for drawing sodium formate Follow these step-by-step instructions to draw the species sodium formate. • Click, hold, and drag to place two carbon atoms (labeled C) connected by a single bond. Double-click one of the C atoms and type the letter o to change the atom to oxygen. Similarly, click once on the bond to change it to a double bond.

Next, choose the letter H from the atom menu, then click and drag from the carbon atom to place a hydrogen atom attached to the carbon atom by a single bond from seo group buy services.

Choose the letter O from the atom menu, then click and drag from the carbon atom to place an oxygen atom attached to the carbon atom by a single bond.

Choose the letter X from the atom menu, then place the X atom near the structure. Double-click the X atom and type Na to create a sodium atom.

Select the negative charge tool and click on the oxygen atom once. Select the positive charge tool and click the sodium atom once.

Finally, click the electron-dot pair button and then click on the oxygen atom to add the correct number of electron dots.

Place one C atom on the grid, change the label to O, and then add two pairs of electron dots. Make certain to include the electron-dot pairs. ANSWER: Hint 3. Draw a C atom single-bonded to an H atom and an O atom To practice drawing single bonds, draw H —C —O. Click within the applet once to place a C-C bond on the grid.

Then select the letter H from the atoms at the bottom. Click a C atom to replace it with an H atom. Then select the letter O from the atom, click, and drag from the C atom to place the single-bonded oxygen atom.

Draw a C atom double-bonded to an O atom To practice drawing a double bond, draw C = O. Click, hold, then drag on the grid to place two atoms connected by a single bond. Click once on the bond to change it to a double bond. Finally, change the label on one of the atoms from C to O.

Draw an Na atom with a positive charge To practice drawing atoms not in the atom menu with a charge, draw Na + . Click More positive charge button ANSWER: to pull up a pe riodic table. Select Na from the periodic table, and close the table. Click to place the atom on the grid. Click the Click on the Na atom once.

Correct Keep in mind that you can refer to this question or consult the Help , if you have difficulty using this answer type later on Introduction to Drawing Organic Structures This exercise is not intended to test your knowledge of any specific subject material. Therefore, on this problem you will not be penalized for submitting incorrect answers.

Copying and pasting atoms or structures requires keyboard shortcuts. For a more detailed description of how to use each button, watch the videos accompanying the parts. You can also access the help at any time when working through an item. Part A Watch the videos about creating, erasing , and adding double and triple bonds. You can also use the hints to learn more about each button.

Then, use the Erase tool to remove the extra —OH group from the structure shown on the canvas. Use the Single [1], Double [2], and Triple [3] Bond tools to draw a chain with three carbon atoms, and edit the bonds to create the structure shown.

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