# Understand Your Learning Questions

##### "What should my chemistry students know before they get to college?"

**Questions by Topic:**

**Laws of Conservation**

**Balancing Chemical Equations:**

**Atomic Structure and the Periodic Table**:

- If an atom gains 2 electrons, what does it become?
- Keywords: ions, anions, cations, electrons, charge

- What are the three types of subatomic particles and their respective charges?
- Keywords: subatomic particles, protons, neutrons, electrons, nucleus, charged particles

- How many neutrons does C-14 have?
- Keywords: isotopes, isotope notation, nuclide notation, hyphen notation, mass number

**Math Fundamentals**

- How would 90,000 be written in scientific notation?
- Keywords: scientific notation

- What is the cube root of 125?
- Keywords: roots, cube root, calculator

- Solve log10100=? and rearrange the completed equation into exponent notation.
- Keywords: logarithms, exponents

Short clips explaining the concept:

**SI Units & Unit Conversions **

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

Short clips explaining the concept:

**Solution Concentration**

- What is the concentration of a solution after you diluted 40 mL of a 6 M solution to prepare 210 mL of this solution?
- Keywords: dilutions, solution, concentration

- How many moles are required to make a 60mL solution of 2.4 mL of nitric acid?
- Keywords: molarity, solution, concentration

**Moles & Molar Mass**

- Calculate the mass, in grams, of 2.89 x 1023 moles of KBr.
- Keywords: Avogadro's Number, moles, molar mass

- How many moles are there in an 8.3 kg sample of C3H6O?
- Keywords: molar mass, unit conversions

**Net Ionic & Acid-Base Equations**

- Write the balanced chemical equation for the reaction between hydromic acid and sodiun hydroxide including the state of each compound.
- Keywords: solubility rules, acid-base reaction, net ionic equation, aqueous state

- What is the final net ionic equation when hydroiodic acid is reacted with lithium hydroxide?
- Keywords: solubility rules, acid-base reaction, net ionic equation, aqueous state

**Stoichiometry & Limiting Reactants**

- How many grams of O2 would you need to react with 5 grams of AI?
- Keywords: stoichiometry, molar mass, gram to mole conversions, stoichiometry with diatomic elements

- When you react 10 grams of AI with 12 grams of O2, which is the limiting reagent and which is the excess reagent?
- Keywords: stoichiometry, molar mass, gram to mole conversions, stoichiometry with diatomic elements, limiting reactant, excess reactant

**Gas Laws unit**

- 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?
- Keywords: Charles's Law, gas laws, volume, temperature

- 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?
- Keywords: Boyle's Law, gas laws, pressure, volume

**Significant Figures**

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

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

Short clips explaining the concept:

**Formulas & Ionic Compounds**

All four questions are answered in this video.

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