Key Concepts Flashcards
What is meant by the conservation of mass in chemical reactions?
That the mass of reactants is equal to the mass of the products.
What is the chemical and word equation for calcium carbonate and hydrochloric acid?
Calcium carbonate + hydrochloric acid —> calcium chloride + carbon dioxide + water
CaCO3 + 2HCl —> CaCl2 + CO2 + H2O
What happens to the mass if a gas is produced during the reaction?
The mass of the reaction would appear to decrease as the gas has escaped into the atmosphere so can no longer be accurately measured.
What happens to the mass if a gas is one of the reactants?
The mass would appear to increase as the gas which couldn’t have been measured before is now being able to be measured.
Go on Google and balance some equations
Check your answers
What is the word and chemical equation for a reaction between lead nitrate and potassium iodide
Lead nitrate + potassium iodide —> lead iodide + potassium nitrate
Pb(NO) + 2KI —> PbI + 2KNO
What is an element
A substance made up of only one type of atom
What is a mixture
2 or more different non chemically bonded substances
Define solvent
A liquid that can dissolve a solute
What does impure mean
A mixture that will melt over a range of temperatures
How do define a pure substance
Something that contains one type of particle and will have a fixed melting point,
How does chromatography determine how soluble an ink is?
The amount that they move depends on how soluble they are in water.
What is the retention factor?
Rf= distance travelled by compound / distance travelled by solvent
What does the retention factor tell us?
Has no units, and is between 0-1. The distance travelled by the SPOT (not dye or ink) relative to the solvent, tells us how soluble it is.
What are group 1 metals referred to as?
Alkali metals
What are group 2 metals referred as?
Alkali earth metals
What are group 7 elements known as
Halogens
What are group 0 known as
Noble gases
What are general properties of metals?
- high melting and boiling points
- good conductors of heat and electricity
- malleable
- dense
What are general properties of non-metals?
- low melting and boiling points
- poor conductors of electricity (except graphite)
- brittle
- dull
- less dense
What is the charge of mass of electrons?
Mass = negligible
Charge = -1
What is the charge and mass of neutrons?
Mass = 1
Charge = 0
What is the charge and mass of protons?
Mass = 1
Charge = +1
What is the atomic number of an elements?
The number of protons
What is the atomic mass of an element?
Protons + neutrons
What is an isotope?
Atoms of an element with the same number of protons but a different number of neutrons
How do calculate the relative atomic mass (Ar)?
(Mass of isotope x % of isotope) + (mass of isotope x % of isotope) / 100
What is the relative atomic mass?
The weighted average of the masses of the isotopes of an element compared to a (relative element)
What is the formula of a hydroxide ion.
OH-
What is the formula of a carbonate ion?
CO3 2-
What is the formula of a nitrate ion?
NO3 -
What is the formula of a sulfate ion?
SO4 2-
What is the formula of an ammonium ion?
NH4 +
