Understand Your Learning Questions

Laws of Conservation

1. A cup of water has a total mass of 80 grams. You put it into the freezer and take it out once it has fully frozen. If you take the mass again, how much will it be now?

Balancing Chemical Equations:

1. Determine if the following chemical equation is balanced or unbalanced: N2 + 3H2 → 2NH3

Atomic Structure and the Periodic Table: 

1.   If an atom gains 2 electrons, what does it become?
   1. Keywords:  ions, anions, cations, electrons, charge
2.  What are the three types of subatomic particles and their respective charges? 
   1. Keywords: subatomic particles, protons, neutrons, electrons, nucleus, charged particles
3. How many neutrons does C-14 have?
   1. Keywords: isotopes, isotope notation, nuclide notation, hyphen notation, mass number

Math Fundamentals

1. How would 90,000 be written in scientific notation?
   1. Keywords: scientific notation
2. What is the cube root of 125?
   1. Keywords: roots, cube root, calculator
3. Solve log10100=? and rearrange the completed equation into exponent notation.
   1. Keywords: logarithms, exponents

 Short clips explaining the concept: 

• How Big is Avogadro's Number 

SI Units & Unit Conversions 

1. Which is larger 2 kg or 6,000,000g?
   1. Keywords: dimensional analysis, unit conversions, kilograms to grams

 Short clips explaining the concept: 

• Calculating the Number of Inches in a Football field using Unit Conversions 

Solution Concentration

1. What is the concentration of a solution after you diluted 40 mL of a 6 M solution to prepare 210 mL of this solution? 
   1. Keywords: dilutions, solution, concentration  
2. How many moles are required to make a 60mL solution of 2.4 mL of nitric acid? 
   1. Keywords: molarity, solution, concentration

Moles & Molar Mass

1. Calculate the mass, in grams, of 2.89 x 1023 moles of KBr. 
   1. Keywords: Avogadro's Number, moles, molar mass
2. How many moles are there in an 8.3 kg sample of C3H6O?
   1. Keywords:  molar mass, unit conversions

Net Ionic & Acid-Base Equations

1. Write the balanced chemical equation for the reaction between hydromic acid and sodiun hydroxide including the state of each compound. 
   1. Keywords: solubility rules, acid-base reaction, net ionic equation, aqueous state
2. What is the final net ionic equation when hydroiodic acid is reacted with lithium hydroxide? 
   1. Keywords: solubility rules, acid-base reaction, net ionic equation, aqueous state

Stoichiometry & Limiting Reactants

1. How many grams of O2 would you need to react with 5 grams of AI?
   1. Keywords: stoichiometry, molar mass, gram to mole conversions, stoichiometry with diatomic elements
2. When you react 10 grams of AI with 12 grams of O2, which is the limiting reagent and which is the excess reagent?  
   1. Keywords: stoichiometry, molar mass, gram to mole conversions, stoichiometry with diatomic elements, limiting reactant, excess reactant

Gas Laws unit

1. A sample of chlorine gas initially at 400C was compressed with a constant pressure from an initial volume of 80 mL to a volume of 25 mL. What is the final temperature of the sample?
   1. Keywords: Charles's Law, gas laws, volume, temperature
2. A 60 L gas sample with an initial pressure of 680 mmHg is expanded to a volume of 120 L What is the final pressure of this complex? 
   1.  Keywords: Boyle's Law, gas laws, pressure, volume

Significant Figures

1. How many significant figures are in the following numerical value: 654.0
   1. Keywords: counting significant figures, significant figures rules

1. How many significant figures are in the following numerical value: 0.0250
   1. Keywords: adding and subtracting with significant figures, multiplying and dividing with significant figures, rounding rules

 Short clips explaining the concept: 

• Counting Significant Figures

Formulas & Ionic Compounds 

All four questions are answered in this video.

1. What is the chemical formula of calcium chloride?
2. Write the name of the ionic compound KBr?
3. Write the chemical formula for ammonium sulfide.
4. What is the name of the compound Mg(OH)2?
   1. Keywords: writing ionic compound formulas, ionic compound nomenclature, naming ionic compounds, polyatomic ions