2Al + Fe2O3 ( Al2O3 + 2Fe (26.98) ( 159.7) (101.96) 124 601 80 b. Al c. 234.3 d. 234 e. 34.1% 1c. A strip of zinc metal with a mass of 2.0g undergoes single displacement reaction with an aqueous solution containing 2.5g of silver(I) nitrate A. Write a balance equation for the above reaction B. Which of the 2 reactants is the limiting reagent? C. Calculate the mass of zinc (II) nitrate formed D. How much excess reagent is left at the end of the reaction?
Who is right, John or Anna? Explain your answer. 3 When 200 g of calcium nitrate, Ca(NO3)2.2H2O is heated at 120ºC the mass decreases by 36 g. (a) Why does the mass decrease? (b) How much calcium nitrate is left after heating? 4 Calculate the molar mass of these compounds: (relative atomic masses: H = 1; N = 14; O = 16; S = 32; Cu = 64; Br = 80; Pb = 207) (a) copper nitrate, Ca(NO3)2 (b) lead bromate, Pb(BrO3)2 (c) ammonium sulfate, (NH4)2SO4 5 The equation for the complete combustion of methane is shown below.
6.02 x 1023 atoms C. 6.02 x 1023 ions B. 6.02 x 1023 grams D. 6.02 x 1023 molecules 5. What ts the correct unit of a formula weight? A. gram B mol C. gram/mol D. mole/gram 6. How many individual atoms are there in 250 grams of O2?
1. Calculate the average atomic mass of silver using the following data: |Isotope |Abundance |Mass | |107Ag |51.84% |106.9051amu | |109Ag |48.16% |108.9048amu | |106.91 amu • 107.87 amu • 108.00 amu • 108.90 amu What is the average mass of one S atom? • 32.07 g • 32.07 amu • 32.07 g/mol • 32.07 mol What is the mass of 3.50 x 1024 Ti atoms? • 47.9 amu • 47.9 g • 5.81 g • 278 g How many C atoms are in 5.50 g of C? • 5.01 x 1022 C atoms • 2.76 x 1023 C atoms • 3.31 x 1024 C atoms • 5.50 x 1023 C atoms How many Cl atoms are in 0.0728 g of PCl3?
Calculate the molarity of an HCl solution if 20.0 mL of it requires 33.2 mL of 0.150 M NaOH for neutralization. 7. Calculate the molarity of a Ca(OH)2 solution if 18.5 mL of it requires 28.2 mL of 0.0302 M HCl for neutralization. The products are CaCl2(aq) and H2O. 9.
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?
Thearesa Lima 1/8/13 Unit 8 – Assignment SC155 – Intro to Chemistry 1. Which is the strongest antacid, on a single-dose basis? Which is the weakest? Explain and show your calculations. Moles of NaOH = 0.05molL Maalox - 0.05mol/L x 24.1mL = 1.205mmol/1000 = .001205 mol Tums - 0.05mol/L x 22.4mL = 1.120mmol/1000 = .00112 mol Mylanta - 0.05mol/L x 20.0mL = 1.00mmol/1000 = .001 mol CVS - 0.05mol/L x 19.9mL = 0.995mmol/1000 = .000995 mol Rennies - 0.05mol/L x 24.4mL = 1.220mmol/1000 = .00122 mol The strongest is CVS brand because less HCI was left over (0.00995) which means it used the least amount of NaOH to neutralize the acid.
8.1 5) Based on the octet rule, iodine most likely forms an __________ ion. A) [pic] B) [pic] C) [pic] D) [pic] E) [pic] Answer: E Diff: 1 Page Ref: Sec. 8.1 6) There are __________ unpaired electrons in the Lewis symbol for an oxygen atom. A) 0 B) 1 C) 2 D) 4 E) 3 Answer: C Diff: 1 Page Ref: Sec. 8.1 7) How many unpaired electrons are there in the Lewis structures of a [pic] ion?
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.
RESULTS The first flask held .305 grams; the second, .454 grams; and the third, .477 grams of unknown gas. According to the ideal gas law, at a pressure of 762.0 mmHg and 16.0ºC, a vessel of 250 ml will contain .0105 moles of gas, while a vessel of 252 ml will contain .0106 moles of gas. Dividing the number of grams of unknown gas contained in each flask by the corresponding number of moles contained in that vessel resulted in a molar mass for each of the flasks. The