C3 - Quantitative Chemistry

    Cards (64)

    • What is the relative atomic mass (A) of an element compared to?
      Mass of an atom of carbon-12
    • How is the relative formula mass (M) of a compound calculated?
      Sum of all relative atomic masses (A)
    • What is the relative formula mass (M) of hydrochloric acid (HCl)?
      36.5
    • Do relative atomic mass (A) or relative formula mass (M) values have units?
      No, they have no units
    • How can atoms be compared to building bricks in a chemical reaction?
      • Atoms can be rearranged like bricks
      • Total mass remains constant
      • Energy is needed for rearrangement
    • What happens to mass in a closed system during a chemical reaction?
      Mass remains constant
    • What occurs in a non-enclosed system during a chemical reaction?
      Mass can change due to gas release
    • What does the law of conservation of mass state?
      No atoms are lost or made
    • How is uncertainty defined in scientific measurements?
      Measure of variability in data
    • What are the two types of errors in measurements?
      Random error and systematic error
    • What causes random errors in measurements?
      Poor technique or faulty equipment
    • What are systematic errors?
      Consistent errors that recur in experiments
    • How is the range of a set of results calculated?
      Difference between largest and smallest value
    • How is the uncertainty of the mean calculated?
      Range divided by 2
    • What is the relationship between reactants and products in a chemical reaction?
      • Mass of reactants equals mass of products
      • No atoms are created or destroyed
      • Total mass remains constant
    • What is concentration in chemistry?
      Amount of substance in a volume of liquid
    • How can concentration be measured in chemistry?
      By mass or number of moles
    • How do you convert cm³ to dm³?
      Divide by 1000
    • What is a mole (mol) in chemistry?
      A measurement used in chemistry
    • What does Avogadro's constant represent?
      Number of particles in one mole
    • What is the value of Avogadro's constant?
      6.02 × 10²³
    • How is the mass of one mole of a substance related to its relative formula mass?
      They are equal in grams
    • How can the number of particles in a substance be calculated?
      Using Avogadro's constant and moles
    • Calculate the number of helium molecules in 10 mol of helium.
      6.022 × 10²⁴
    • What is the process for determining masses in chemical equations?
      1. Write relative atomic mass (A) for elements
      2. Write relative formula mass (M) for compounds
      3. Use these values in calculations
    • How do you calculate the mass of water produced from burning 300g of methane?
      Use balanced equation and relative masses
    • What is the balanced equation for burning methane?
      CH₄ + 2O₂ → 2H₂O + CO₂
    • How do you calculate the mass of water produced from 16g of methane?
      Use the balanced equation and relative masses
    • How do you calculate the number of moles in 330g of K₂S?
      moles = mass ÷ Mr
    • How do you calculate the mass of 0.9 moles of Fe(NO₃)₃(H₂O)₉?
      mass = moles × Mr
    • What is the concept of limiting reactants in a chemical reaction?
      • Reactant that is completely used up
      • Determines amount of product formed
      • Other reactants remain in excess
    • How do you balance chemical equations using masses?
      1. Write balanced equation
      2. Calculate mass of limiting reactant
      3. Use A and M of reactants and products
    • How do you determine the balanced symbol equation for magnesium and oxygen reaction?
      Calculate moles and divide by smallest
    • What is the balanced equation for magnesium oxide production?
      2Mg + O₂ → 2MgO
    • How do you calculate the amount of each reactant in a reaction?
      Use mass and relative atomic mass
    • How do you determine the limiting reactant in a reaction?
      Identify reactant used up first
    • What is the significance of the limiting reactant in a chemical reaction?
      Determines the maximum amount of product
    • How do you calculate the maximum mass of a product formed?
      Use balanced equation and limiting reactant
    • How do you find the balanced symbol equation for magnesium reacting with oxygen?
      Calculate moles and balance the equation
    • How do you calculate the amount of magnesium and oxygen in a reaction?
      Use their relative atomic masses