Dimensional Analysis
This is the total number of significant figures that should be reported in the final answer if you subtract 20. grams from 120.0 grams.
What is 2? (What is 2 sig figs?)
This fundamental chemical law states that matter cannot be created or destroyed, explaining why all chemical equations must be balanced.
What is the Law of Conservation of Mass?
If the absolute temperature of an ideal gas sample is doubled inside a container while its volume is simultaneously held completely constant, the internal pressure changes by this factor.
What is doubled (multiplied by 2)?
This is the calculated molarity of an aqueous solution containing 0.1 mols of solute dissolved in a final total solution volume of exactly 50 mL.
What is 2 M?
Looking at their molecular valence structures, breaking one mole of diatomic nitrogen gas (N2) requires significantly more energy than breaking one mole of diatomic oxygen gas (O2) for this precise structural reason.
What is nitrogen contains a triple covalent bond, whereas oxygen only contains a double covalent bond?
Convert 33 square centimeters (cm2) to square millimeters (mm2).
What is 3300 square millimeters (must have sig figs and units!)
When balancing the complete combustion reaction of butane (C4H10) using the lowest possible whole-number coefficients, this is the coefficient required for oxygen gas (O2).
What is 13?
For the reaction N2(g) + 3H2(g) --> 2NH3(g), if 3L of hydrogen gas react completely with excess nitrogen at a constant temperature and pressure, this is the total volume of ammonia gas produced.
What is 2 liters?
To dilute 50 mL of a highly concentrated 6.0M HCl stock solution down to a milder concentration of 2.0M, you must add this specific volume of pure water.
What is 100mL (or 0.1L)?
Equal masses of solid iron (specific heat capacity = 0.45 J/goC) and solid gold (specific heat capacity = 0.13 J/goC) absorb identical amounts of thermal energy. If the gold's temperature jumps by 30oC, the iron's temperature will change ________ (more/less) because ___________.
What is less because it has a higher heat capacity so it takes more energy to increase its temperature?
A pure sample of an iron oxide compound is analyzed and found to contain 1.0 moles of iron atoms for every 1.5 moles of oxygen atoms. This is the correct empirical formula for the compound.
What is Fe2O3?
When aqueous solutions of ammonium carbonate and calcium chloride are mixed together, a double-replacement reaction occurs. These are the two products produced (name + chemical formula).
What are calcium carbonate (CaCO3) and ammonium chloride (NH4Cl)?
A rigid container holds a gas mixture consisting of 1 mole of argon gas and 3 moles of helium gas. If a pressure gauge reads a total internal pressure of 8 atm, this is the partial pressure exerted solely by the argon.
What is 2 atm?
Based on the reaction 2HCl + CaCO3 --> CaCl2 + CO2 + H2O, this is the volume of 0.50M HCl needed to completely react with 0.050 moles of solid calcium carbonate.
What is 0.20L (or 2.0x102 mL)?
In a bond enthalpy calculation, if the total energy required to break all reactant bonds is 1,500 kJ and the total energy released when forming all product bonds is 2,200 kJ, the overall reaction must be classified by this thermodynamic term.
What is exothermic? (the enthalpy change for the reaction is -700 kJ)
Calculate the density of a substance that has a mass of 1.00 g and a volume of 0.10 mL.
What is 10. g/mL? (sig figs and units!)
In the synthesis reaction 2H2 + O2 --> 2H2O, if you begin the process with 4 moles of hydrogen gas and 3 moles of oxygen gas, this many moles of excess oxygen gas will remain entirely unreacted.
What is 1 mole?
An ideal gas sample undergoes a simultaneous change where its absolute temperature is tripled while its internal pressure is cut to one-third of its original value. This is the exact factor by which the final volume changes.
What is multiplied by 9? (Increased by a factor of 9)
An unknown aqueous solution is tested in a lab and found to have a pOH value of 11. This is its exact hydrogen ion concentration ([H+]).
What is 1x10-3 M?
A 50.g sample of liquid water at 22oC absorbs exactly 1,000 J of heat. Assuming the specific heat capacity of water is 4.184 J/goC for this calculation, this is the resulting final temperature of the sample.
What is 27oC? (deltaT is 5oC rounded for sig figs)
A gaseous compound has an empirical formula of NH2 If its molar mass is experimentally determined to be 32 g/mol, this is its correct molecular formula.
What is N2H4?
Reactant X (molar mass = 10 g/mol and Reactant Y (molar mass = 20 g/mol) react in a strict 1:1 mole ratio. If you mix equal masses of reactant X with reactant Y, this reactant limits the reaction.
What is reactant Y?
If separate containers of light helium gas and heavy argon gas are maintained at the exact same temperature, this specific gas will feature a higher average molecular velocity.
What is helium? (smaller molar mass)
If a chemist thoroughly mixes 100 mL of 0.10M HCl with 50mL of 0.12M NaOH, what is the pH after the reaction?
What is 1.6?
A 10g block of Metal X (c = 0.20 J/goC) and a 10g block of Metal Y (c = 0.40 J/goC) are both heated to 100oC and dropped into separate, identical water baths at 20oC. This specific metal will cause a smaller temperature increase in its water bath.
What is metal X? (Metal X has a small heat capacity than metal Y).