6. How many moles of NaCl are in 250. mL of a 0.200 M solution? 1. 15.8 g of KCl is dissolved in 225 mL of water. Calculate the molarity.
Name: ___________________________________ Date: ______________ Practice Test #3 ____ 1. When a precipitation reaction occurs, the ions that do not form the precipitate A) evaporate B) are cations only C) form a second insoluble compound in the solution D) are left dissolved in the solution E) none of these 2. An aqueous solution of potassium chloride is mixed with an aqueous solution of sodium nitrate. The complete ionic equation contains which of the following species (when balanced in standard form)? A) B) C) D) E) ____ 3.
5. Nitrogen has two naturally occurring isotopes N-14 and N-15, whose atomic masses are 14.0031 and 15.00001, respectively. The atomic mass of nitrogen is 14.0067. What are the percentages of each of the isotopes? 6.
4) When naming an ionic compound, which ion is given first? The metal ion is named first 5) Give explanations for the following: a. Argon will not react with any other element It already has a complete number of eight, a full number in its valance shell so it cannot react with itself or another element b. The reaction between sodium chloride gives out a lot of heat and light. The chemical energy of the product is less then the chemical energy of the reactants. This energy is indestructible and is converted to light and heat.
How many moles of gas does it take to fill a 1.0 L flask at a pressure of 1.5 atm at 100 celsius? (.049 mol) 2. What is the atmospheric pressure if the partial pressures of nitrogen, oxygen and argon are 604.5 mm Hg, 162.8 mm and .5 mm respectively? (767.8 mm Hg) 3. Describe the
12 10 32. A right triangle has legs of 15 units and 20 units. What is the measure of the hypotenuse? 33. This quadrilateral is most specifically a _________________________ 34.
Mariam Choudhery 11/19/10 P 2 Understanding the Mole Lab Substance | Volume of one mole or (mL or cm3) | Mass of empty beaker (if applicable) | Mass of one mole of substance + beaker (g) | Mass of one mole of substance (g) | Smallest unit of the substance? (atom or compound) | Column :7 | % Error of (molar mass) | SucroseC12 H22O11 | 450mL | 223 | 570.0 | 347g | Compound | .80 | 1.361% | Carbon (C) | 10.8cm3 | N/A | N/A | 10.9g | Atoms | 1.40 | 9.242% | Tin (Sn) | 20 mL | 31.2g | 115.9g | 84.7g | Atoms | 3.81 | 28.65% | Zinc (Zn) | 15mL | 31.2g | 81.90g | 50.7g | Atoms | 5.359 | 22.47% | Aluminum (Al) | 20mL | 31.2g | 55.31g | 24.11g | Atoms | 2.6 | 10.64%/ | Copper (Cu) | 11mL | 31.2g | 95.0g | 63.8g | Atoms | 1.22 | -0.393% |
A. 0.420 M B. 0.567 M C. 0.042 M D. 0.325 M _____ 3. What is the freezing point of an aqueous glucose solution that has 25.0 g of glucose, C6H12O6, per 100.0 g of H2O ? (Kf for water = 1.86 °C /m) A.
How many multiple bonds (double and/or triple) are there in this molecule? (1 point for each molecule) There are no double or triple bonds on this molecule. CO2 4+2(6)=16 .. .. O = C = O .. .. 1. What is the central atom? (1 point for each molecule) The central atom is C. 2.