Consider the following reaction: ___ Al (s) + ___ I2 (s) ---> ___ AlI3 (s) . What is the coefficient in front of the I2(s), when the reaction is balanced to lowest whole number coefficients? A. 2 B. 1 C. 3 D. 4

How many electrons are transferred in the following reaction when balanced? (The reaction as written is unbalanced.) Mg2*(aq) Mg(s) + Al3+(aq) –→ Al(s) + А. 4 В. 2 С.6 O D. 1 O E. 3

10. When the equation below is balanced, the coefficient in front of carbon dioxide is C3H8 + O2 --> CO2 + H2O: A. 1 B. 3 C. 6 D. 12

CHEMICAL Zn (s) ASH3 (g) Zn2* (aq) REACTION: H3ASO4 (aq) + (in acidic solution) Red Separate into ½ reactions Ох Balance elements (except O and H) Add H20 to balance O Add H* to balance H Add e to balance charges Multiply 2 reactions to yield equal number of e Combine 2 reactions Simplify Check for balanced Reactants Products atoms AND charges

Multiple Choice. Read the statements carefully and answer the following questions.For no.7, 8, 9 and 10 refer to the chemical equation.REACTANTS PRODUCTN2 + 3 H2 -------→ 2 NH37. For the product 2 NH3 , What number represents the coefficient ?a. 1 b. 2 c. 3 d. none8. What number represents the subscript?a. 1 b. 2 c. 3 d. none9 What element is represented by the letter “ H “a. Hydrogen b. Helium c. Hydroxide10. How many atoms of “ H “ do you have ?a. 2 b. 3 c. 4 d. 6

Which of the following chemical equations is a correct dissociation equation a. NaCl(s) > Na+1 +Cl-1(aq) b. C2H5(OH) > C2H5OH(aq) c. LiOH(s) > Li+1(aq) +O-2(aq) d. C2H5OH(l) > C2H5O-1 +H+1(aq)

Please answer all parts of this question. 1. Magnesium oxide can be made by heating magnesium metal in the presence of oxygen gas. a. Write the balanced equation, including phase symbols. b. When 10.1 g of magnesium reacts with 10.5 g of oxygen gas, 11.9g of magnesium oxide is collected.       i. Determine the limiting reactant      ii. Determine the theoretical yield    iii. Determine the percent yield for the reaction

a reaction mixture initially contains 0.25 moles of ZnS and 0.25 moles of O2. after the reaction is complete. how many ,oles of the excess reactant are left over?  2 ZnS+3 O2---> + 2 SO2 0.250 moles O2 0.125 moles O2 0.083 moles ZnS 0.167 moles ZnS

Chemistry Question

43. Find the limiting reactant for each initial amount of reactants. MISSED THIS? Read Section 4.40; Watch KCV 4.4, IWE 4.6 2 Na(s) + Br2(g) → 2 NaBr(s) a. 3 mol Na, 1 mol Br₂ b. 2.8 mol Na, 1.1 mol Br₂ c. 1.5 mol Na, 2.1 mol Br₂ d. 11.5 mol Na, 5.5 mol Br₂