What strategy should be used to convert a given mass in grams of sodium chloride into the number of molecules of the same substance?
This can be achieved in two steps: 1. The grams of a substance can be converted to the number of moles of a substance using its molecular weight. The molecular weight of sodium chloride, denoted NaCl, can be determined from a periodic table. The molecular weight of Na is 23.0 g/mol and the molecular weight of Cl is 35.5 g/mol. Because NaCl is made up of a 1:1 ratio of these atoms, the molecular weight of NaCl is 1*23.0 g/mol + 1*35.5 g/mol = 58.5 g/mol. To convert grams to moles, divide the number of grams of NaCl by this molecular weight. 2. The number of moles of a substance can be converted to the number of molecules using Avogadro's number, 6.022 * 10^-23 1/mol. To turn the number of moles (from Step 1) into the number of molecules, multiply the number of moles by Avogadro's number.
Name and briefly describe the three steps of addition polymerization.
1. Initiation A radicial initiator reacts with a monomer to form a radical, as described by the chemical equation: M + R* --> M* + R 2. Propagation The radicalized monomer reacts with other monomeric units to form a polymer chain, as descirbed by the chemical equations: M* + M --> M-M* M-M* + M --> M-M-M* M-M-M* + M --> M-M-M-M* And so forth 3. Termination The growing polymer chains are either terminated by combination or disproportionation. In combination, the radical groups at the end of two polymer chains react to form a linkage. In disproportionation, the radical group at the end of one chain reacts with the atom adjacent to the radicalized atom in another chain; in this situation, only the former chain is terminated, while the latter continues growing.
Determine the dimensions of a rectangle with a perimeter of 200 cm, given that its length is equal to three times its width.
The best way to tackle this problem is breaking down the question into equations for each set of information that is given. The problem begins by noting that the rectangle's perimeter is 240 cm. Using the idea that the perimeter of a rectangle is 2*length + 2*width, we can write down the equation: 2*l + 2*w = 240 cm. The problem ends by telling us that the length of the triangle is three times it's width. We can write this equation as: l = 3*w By plugging the second equation into the first, we get 2*(3*w) + 2*w = 240 cm We can solve this equation to find the width: 6*w + 2*w = 240 cm 8*w = 240 cm w = 30 cm Returning to the second equation, l = 3*w, we can now find the length. l = 3 * 30 cm l = 90 cm