Questions asked by Pickle

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• A fictitious element that has two isotopes has an average atomic mass of 117.3. If 65.43% of the atoms of the element have an atomic mass of 119.8, what is the atomic mass of the other isotope?
  
• What is the sum of the coefficients when the following equation is balanced with the simplest whole numbers? If a substance has an understood 1 as the coefficient, do not forget to add it in. Fe2O3 (s) + C (s) → Fe (s) + CO2 (g)
  
• What is the mass % of H in C9H10N2?
  
• What mass of hydrogen atoms are in 166 g of zinc hydroxide: Zn(OH)2 (Mw. 99.43)?
  
• What mass of iron(III) oxide is required to produce 12.8g of iron? 2Fe2O3 + 3C → 4Fe + 3CO2
  
• If 20.6mol of carbon dioxide is produced in the reaction below, how many moles of water is also produced? 2 C2H6 + 7 O2 → 4 CO2 + 6 H2O
  
• What mass of sodium nitride is required to produce 14.5g of nitrogen? 2Na3N → N2 + 6Na
  
• If 14.6 mol of iron(III) oxide and 17.5 mol of carbon react, what is the maximum number of moles of iton that can be recovered from the reaction? 2 Fe2O3(s) + 3 C(s) → 4 Fe (s) + 3 CO2(g)
  
• If 44.9 g of iron(III) oxide and 19.9 g of carbon react, what is the theoretical yield in grams of iron metal? 2 Fe2O3(s) + 3 C(s) → 4 Fe (s) + 3 CO2(g)
  
• If 11.1 mol of iron(III) oxide and 22.7 mol of carbon react, how many moles of the excess reactant will remain after the reaction? 2 Fe2O3(s) + 3 C(s) → 4 Fe (s) + 3 CO2(g)
  
• Sulfur hexafluoride can be synthesized by burning sulfur with fluorine. What is the percent yield of the reaction if 76.8 g of sulfur hexafluoride is recovered from the combustion of 28.7 g of sulfur? S8(s) + 24 F2(g) → 8 SF6 (g)
  
• How do you write the net ionic equation for the complete molecular equation? 3 BaCl2 (aq) + 2 (NH4)3PO4 (aq) --> Ba3(PO4)2 (s) + 6 NH4Cl (aq) ______(aq) + ______(aq) --> _______(s) Symbol of positive spectator ion: Symbol of negative spectator ion:
  
• What volume (in mL) of 9.91 M sodium chloride is required to produce 100.0 mL of a 0.398M solution?
  
• Energy change is the sum of heat and work: ΔE = q + w. Work is calculated by: w = -PΔV What is the change in energy (in joules) if a reaction absorbs 40.3 J of heat and increases in volume from 0.250L to 0.750L at a constant pressure of 1.056 atm?
  
• What is the limits?
  
• How do you find the limits?
  
• What is the limits?
  
• What is the limits?
  
• Which of the following is the reaction associated with the electron affinity of magnesium? -Mg(g) → Mg+(g) + e- -Mg(g) → Mg2+(g) + 2e- -Mg(g) + 2e- → Mg2-(g) -Mg(g) + e- → Mg-(g) -Mg(g) → Mg-(g) + e-
  
• Compare the structures of SO3 to PF3 and explain why they have different molecular shapes?
  
• What is the area of the region bounded between the graphs of y= -x^2 + 8x and y =x^2 + 2x?
  
• Let R be the region bounded by y=4/(x^3), y=1/2 and x=1. What is R if it revolved around the line y = -2?
  
• A substance has a density of 4.72 kg/dm3. What is its density in g/cm3?
  
• A block has a surface area of 0.14 cm2. What is its surface area in mm2?
  
• Convert 7.03 x 1012 nm3 to mm3?
  
• What mass of aluminum oxide can be recovered from the complete reaction of 30.4 g of Al with 30.4 g of oxygen gas? 4 Al (s) + 3 O2(g) → 2 Al2O3(s)
  
• If 13.3 moles of Cu and 43.2 moles of HNO3 are allowed to react, how many moles of excess reactant will remain if the reaction goes to completion? 3 Cu + 8 HNO3 → 3Cu(NO3)2 + 2NO + 4H2O