What volume of concentrated (18.0 M) sulfuric acid would be required to make each of the following? a. 1.25 L of 6.00 M solution Mconc x Vconc = Mdil x Vdil (18.0 M) x (Vconc) = (6.00 M) x (1.25 L) Vconc=0.417 L b. 575 mL of 0.100 M solution Mconc x Vconc = Mdil x Vdil (18.0 M) x (Vconc) = (0.100 M) x (0.575 L) Vconc=0.00319 L Acid-Base Titrations 5. Calculate the molarity of an HCl solution if 20.0 mL of it requires 33.2 mL of 0.150 M NaOH for neutralization.
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?
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. CH4 + 2O2 → CO2 + 2H2O When 80 g of methane is completely combusted, 220 g of carbon dioxide and 180 g of water are formed. (a) Why is the mass of carbon dioxide formed greater than the mass of methane burnt? (b) Calculate the mass of oxygen that reacted. (c) Calculate the mass of water formed when 20 g of methane undergoes complete combustion.
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?
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?
Which of the following mass units is the largest? a.|1 cg|c.|1 mg| b.|1 dg|d.|1 ng| 9. If the temperature changes by 100 K, by how much does it change in C? a.|0C|c.|100C| b.|37C|d.|273C| 10. What is the quantity 987 milligrams expressed in grams?
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
The RQ was 0.79, which indicates that the 33% of the kcal that the subject was using came from carbohydrates and that 67% of the kcal came from fat. In the 100W stage the volume of carbon dioxide was 4.08L/min and the volume of oxygen consumed was 4.1L/min. The RQ came out o be 0.99, the substrate being used was only carbohydrates at this point. The 200w stage had a carbon dioxide volume of 7.91L/min and a oxygen consumed volume of 6.51L/min. The RQ was 1.2 which indicates that the body is producing more carbon dioxide than the oxygen being consumed.
Using the periodic table, determine the result of the following calculation: the number of electrons in the outer shell of a hydrogen atom minus the number of electrons in the outer shell of a helium atom plus the number of electrons in the outer shell of a hydrogen atom. • 8 electrons, minus 2 for the first orbital, second orbital will have 6 making them valence 5. When is an electron a valence electron? Why are valence electrons especially important in chemical reactions? • When it is on the very outside level away from the nucleus A valence electron is one that occupies the highest energy level for any electron in a particular neutral atom.
A) 159 B) 430 C) 601 D) 720 E) 760 Answer: A Diff: 1 Page Ref: Sec. 18.1 7) What is/are the product(s) of photodissociation of molecular oxygen? A) molecular nitrogen B) excited oxygen molecules C) ozone D) ozone and atomic oxygen E) atomic oxygen Answer: E Diff: 1 Page Ref: Sec. 18.2 8) The C-Cl and C-F bond dissociation energies in [pic]are 339 kJ/mol and 482 kJ/mol, respectively. The maximum wavelengths of electromagnetic radiation required to rupture these bonds are __________ and __________, respectively.