Question

17) Which of the following is TRUE? A) Stoichiometry allows prediction of how much of the reactants are necessary to form a given amount of product. B) Stoichiometry shows the numerical relationship between chemical quantities in a balanced chemical equation. C) Stoichiometry allows prediction of the amounts of products that form in a chemical reaction based on the amounts of reactants D) All of the above are true. E) None of the above are true. 18) Diatomic O2 can react with the element magnesium to form magnesium oxide (MgO). The balanced chemical equation is: O2+2 Mg 2 MgO If 4 moles of magnesium totally reacted with more than enough O2 how many moles of MgO would be expected to form? A) 1 mole 18) B) 2 moles C) 8 moles D) 4 moles E) not enough information 19) 19) How many moles of Ha can be made from complete reaction of 3.0 moles of Al? Given: 2 Al+6 HCI-2 AICI3 3 H2 A) 3 moles B) 3.0 moles C) 9.0 moles D) 4.5 moles E) none of the above 20) Suppose two chemical reactions are linked together in a way that the O2 produced in the first reaction goes on to react completely with Mg to form MgO in the second reaction. Reaction one: 2 KCIO3 302+2 KCl Reaction two: 2 Mg+O2-2 MgO If you start with 4 moles of KCIO3, how many moles of MgO could eventually form? 20) A) 6 moles B) 4 moles C) 12 moles D) 2 moles E) none of the above 21) How many grams of water are made from the reaction of 16.0 grams of oxygen gas? Given the reaction: 2H2 O2 21120 21) A) 16 B) 9 C) 36 D) 18 E) not enough information A-4

Answer 1

Aymer - ) all the aloue au true 2 + 2 mg ergo - 2 2 mol ug 2 mol Mgo moles of Mgo - 4 mol - Ans - D) 4 moles 19) 2 A 2 Ad + 6HC 2Al3 + 3 H₂ 2 rol Ada 3 mol H2 3 mol Ad ? moley of Hz fomed = 343/2 1 = 4. 5moly Ans - D) 4.5 roly 20) 2 mol k doz 3 mol O₂ 4 mot koloz 2 mol Mgo Auso - D) 2 moly. 21 ) 2H2 + 2H20 - 32g 36g 169 ? mass of water = 16+36/32 2189 Ans: o) is