11. How many moles of Cl_(2) gas are in a 5.60L sample at STP?
Choose the proper coefficients for each substance to balance this equation. underline ( )X_(3)Y_(8)+underline ( )Z_(2)arrow underline ( )XZ_(2)+underline ( )Y_(2)Z 1,3,2,2 1,5,3,4 1,3,4,2 1,2,4,2
When [Ag^+]=1.29M the observed cell potential at 298 K for an electrochemical cell with the reaction shown below is 2.082 V. What is the Mn^2+ concentration in this cell? 2Ag^+(aq)+Mn(s)arrow 2Ag(s)+Mn^2+(aq) [Mn^2+]=square mol/L
Ethanol is a possible fuel. Use average bond energies to calculate Delta H_(rxn) for the combustion of ethanol. CH_(3)CH_(2)OH(g)+3O_(2)(g)arrow 2CO_(2)(g)+3H_(2)O(g) Delta H_(rxn)=? 0.1124 mathrm(~kJ) & 0.1245 mathrm(~kJ) & 0.894 mathrm(~kJ) & 0.2213 mathrm(~kJ) & -754kJ
2. What volume of NH_(3) at STP is produced if 25.0 g of N_(2) is reacted with an excess of H_(2) N_(2)+3H_(2)arrow 2NH_(3)
54. The rate constant of the reaction Cl+CHCl_(3)arrow HCl+CCl_(3) is 5.8times 10^7M^-1s^-1 at 25^circ C and has an activation energy of 11.0kJ/mol. Calculate the rate constant for this reaction in the lower stratosphere where the temperature is -57^circ C 4.9times 10^9M^-1s^-1 1.1times 10^7M^-1s^-1 4.2times 10^7M^-1s^-1 2.7times 10^9M^-1s^-1 9.5times 10^6M^-1s^-1
Sulfuric acid, H_(2)SO_(4)(aq) can be used to neutralize barium hydroxide, Ba(OH)_(2)(aq) . What is the formula of the salt produced by this neutralization?
5 C_(3)H_(8)+O_(2)arrow CO_(2)+H_(2)O If 20 gof propane burn in oxygen how many grams of water are produced? Chem (H) only: How many molecules of water are produced? a. Balance b. Given/Required c. Solution
1. Given the following reaction: underline ( )C_(3)H_(8)+underline ( )O_(2)arrow underline ( )CO_(2)+underline ( )H_(2)O a. Balance the equation first b. Determine the limiting reagent if you start with 14.8 g of C_(3)H_(8) and 3.44 g of O_(2) c. Determine the number of moles of carbon dioxide produced d. Determine the number of grams of H_(2)O produced e. Determine the number of grams of excess reagent left over after the reaction.
Calculate the number of nitrogen atoms in a 110.0 g sample of hydrazine (N_(2)H_(4)) Be sure your answer has a unit symbol if necessary, and round it to 4 significant digits.
How many protons are in an atom of carbon with 7 neutrons? a) 6 b) 7 c) 12.01 d) 13 e) None of the above
How many electrons are in the element potassium with 20 neutrons? a) 19 b) 20 c) 39 d) 39.10 e) None of the above
An erlenmeyer flask has a calibration of 50 mL. To what value can you estimate a measured volume? the nearest 0.01 mL the nearest 1 mL the nearest 0.1 mL the nearest 10 mL
2. Can you determine conclusively that an unknown substance contains only magnetite by using only a magnet? Explain your answer. __
Before you go, which type of molecule would you choose to be the anode in a lithium battery? a) The metal with the most negative potential b) It does not matter since lithium's potential is so negative c) The metal with the most positive potential d) Another lithium compound
$2Fe_{2}O_{3}(s)+3C(s)\rightarrow 4Fe(s)+3CO_{2}(g)$ Calculate the mass of iron produced from the complete reaction of 64.0 grams of iron (III)oxide. 89.5 g Fe 22.48 Fe 11.2 g Fe 44.88 Fe 107 g Fe
QUESTION Q Which of the following is true concerning mass number? ANSWER Using mass number notation, we can identify the number of protons. electrons.and neutrons. Isotopes differ in their numbers of electrons. The mass number is equal to the number of protons. Thus, the mass number of Helium is 2. The mass of electrons contributes significantly to mass number. IDONT KNOWYET
Multiple Choice Question If phenol red is added to a solution with a pH of 9.0, it will appear __ pink-red yellow
What precipitate forms when mixing silver(I)nitrate and sodium chloride? silver(I) chloride sodium nitrate no precipitate forms
Which of these equations correctly expresses the self-ionization of water? $H_{2}O+H_{3}O^{+}\leftrightarrow H_{2}O+OH^{-}$ $H_{2}O+H_{2}O\leftrightarrow 2OH^{-}$ $H_{2}O+H_{2}O\leftrightarrow 2H_{3}O^{-}$ $H_{2}O+H_{2}O\leftrightarrow H_{3}O^{+}+OH^{-}$
