(c) Calculate the mass of water formed when 20 g of methane undergoes complete combustion. 6 Deduce the empirical formulae of the following: Moles and empirical formulae 1 Calculate the molar mass of these compounds. (Relative atomic masses H = 1; N = 14; O = 16; Mg = 24; S = 32; Ca = 40; K =39; Cr = 52; Fe = 56.) (a) calcium ethanoate, Ca(CH3CO2)2 (b) chromium sulfate Cr2(SO4)3 (c) magnesium hydroxide, Mg(OH)2 (d) potassium cyanoferrate(III), K3Fe(CN)6 2 When 2.4 g of magnesium
8.1 7) How many unpaired electrons are there in the Lewis structures of a [pic] ion? A) 0 B) 1 C) 2 D) 3 E) This cannot be predicted. Answer: A Diff: 1 Page Ref: Sec. 8.1 8) How many unpaired electrons are there in an [pic] ion? A) 0 B) 1 C) 2 D) 3 E) This cannot be predicted.
i. What is the hydrogen concentration of a solution with a pOH of 3.7? j. What is the pH of a substance with a hydroxide concentration of 4 x 10-5? k. What is the hydroxide concentration of a substance with a pOH of 8.5?
Find density of the metal. Data Unknown Liquid - Ethanol Mass of Flask | Volume of flask | Mass of Unknown Liquid | Density of Liquid | Actual Density of Liquid | 35.404 g | 23.5 mL | 54.373 g | .807 g/mL | .7893 g/mL | 35.2522 g | 24.09 mL | 54.9811 g | .8190 g/mL | .7893 g/mL | % Error = Unknown Solid – Lead Mass of Flask | Mass of Flask with Solid | Mass of Flask with Solid and Water | Density of Solid | Actual Density of Solid | 35.404 g | 88.824 g | 107.438 g | 11.06 g/mol | 11.3 g/mol | 35.2522 g | 102.9019 g | 119.4321 g | 9.01 g/mol | 11.3 g/mol | % Error = Conclusion Questions 1. A. Mass of water = 60.735 g – 31.601 g = 29.134 g B. Volume of water = Volume of flask = 29.134 g = 29.213 cm3 0.9973 g/cm 2.
What is the measurement 111.009 mm rounded off to four significant digits? a.|111 mm|c.|111.01 mm| b.|111.0 mm|d.|110 mm| 7. What is the temperature of absolute zero measured in C? a.|–373C|c.|–173C| b.|–273C|d.|–73C| 8. Which of the following mass units is the largest?
What element has 11 protons? If an ion had 17 protons and 18 electrons, it would be a negative ion. These are called anions. What element has 17 protons? Atoms and Ions Atoms have no net charge.
6. Copper has two stable isotopes,[pic]and [pic], with masses of 62.939598 amu and 64.927793 amu, respectively. Calculate the percent abundances of these isotopes of copper. 7. Chromium has four naturally occurring isotopes: chromium – 50 (4.35% at 49.946 amu) chromium – 52 (83.79% at 51.941 amu) chromium – 53 (9.50% at 52.941 amu), and chromium – 54 (2.36% at 53.939 amu) Calculate the average atomic mass of
Multiple Choice and Bimodal 1) Solids have a __________ shape and are not appreciably __________. A) definite, compressible B) definite, incompressible C) indefinite, compressible D) indefinite, incompressible E) sharp, convertible 2) __________ is the chemical symbol for elemental sodium. A) S B) W C) So D) Na E) Sn 3) If matter is uniform throughout, cannot be separated into other substances by physical processes, but can be decomposed into other substances by chemical processes, it is called a (an) __________. A) heterogeneous mixture B) element C) homogeneous mixture D) compound E) mixture of elements 4) The symbol for the element potassium is __________. A) Pt B) P C) K D) S E) Ca 5) The symbol for the element magnesium is __________.
• The electron, the proton and the neutron are the "building blocks" of the atom. Protons have a positive electrical charge (p+), and neutrons which have about the same mass, are electrically neutral, or have no electrical charged (n0). Electrons, which are much less massive than protons - only about 1/1836th as heavy - have a negative electrical charge (e-). All atoms are made of protons, neutrons and electrons, though most hydrogen (1H1) has just the proton in its nucleus and a lone electron in orbit. 3.
3) One gram = 6.02 x 1023 amu. The mass of 1.66E-24g is 3.63 x 1047 4)If an atom has the amu of 197 it is Gold because gold is rounded of to 197 from