Question

2.1 MULTIPLE CHOICE 1) Which element has the chemical symbol, P? Al lead B) phosphorus platinum D) potassium to water is formed if 3.2 of methane reacts with 12. Me react to form carbon code and water. What of open to produce 3.3 o carbon dioxide? A1724 14.88 DJ 160 3) Which of the following two whom we stopes? 2.2 OTHER QUESTIONS (Fill in the blank, TRUE or FALSE and calculations) On and Complete the sentences in questions and using one of the following definite proportions energy conservation multiple proportions The observation that of hydrogen reacti o n hydrogen reacts with 40 of wygen to form the same product th to form a product with mass ratio 1 and 60g of a t is evidence for the law of 5) The observation that hydrogen and oxygen can react to form two compounds with different chemical and physical properties, one having an Osmass ratio 1 and the other having OH mass ratio 161 consistent with the Law of An element has two naturally occurring isotopes. One has an abundance of 37.4and an isotopic mass of 184.953 , and the other has an abundance of 62.6 and a mass of 186 956 amu. What is the atomic weight of the element? SHOW WORKINGS pois Chapter 3 Mass Relationships in Chemical Reactions Relative atomic masses (g/mol): C 12.01; Ca; 40.08; Co 58.93; H 1.008; N 14.01; 16.00, S 32.07 3.1 ATULTIPLE CHOICE en the chemical equation N2 3 2 2 NH On a macroscopie level, what do the coefficients mean? All arom of nitroen reacts with atoms of hydrogen to give 2 atoms of ammonia I move of nitroen reacts with 3 moles of hydrogen to give 2 moles of ammonia. CI movecue of nitrogen reacts with 3 molecules of hydrogen to give 2 molecules ot amonka DJ AN of these are true. the Sun of the coefficients when the following equation is balanced using the lowest whole numer B2O3(s) + HF() ► BF319) H2on B) 11 C) 15 D) none of these

Answer 1

1 Pb A. Lead Bi Phosphorus - Ici Platinumie .. Polassium - P Pt ķ Answer : (B) Phosphorus. CH4 +202 CO₂ +2420 Moles of CH4 = 3.24 0.2 med 16.gmalt Molus of O2 = 12.89 0.4 mel. - 32 gmert Imole chu reacts with 2 mole of O₂ inclicates that cry and O2 consumes completely during this reaction. I mele Chy forms 2 mell of H₂O ... 10.2 mol will form 2 moles H₂O x 0.2 mol CHY . Imel Chu - -004 mole. He 0. mass of H₂O=0.4 mét x 18 gmert = 7.29 (A) (3) Isotopes have the same number of protons Latomic number) but different number of neutrons (mass humbertian

Anelement | Mass number representation 1. Xt symbel . Alomic number : L. Ar und ya.. and 20 Co. Same mass number Different atomic number these are isotopes . . By Gc and 6 but Same atomic different mass number number. (c) and (o) also wrong